Grogar hasn't featured in my fics so far but in my ficseries headcanon, he's kind of a big player in the history of Equestria and the world outside it. Regardless, I hope you enjoy my take on his Start Of Darkness...

Around three thousand years before Equestria was founded, in the vast harem of the Brominian Palace in the city of old Gongros, the capital of the ancient and glorious goatish empire of Gith, Concubine Yantan-Tethera gave one last howl of agony before dying in childbirth.
The first death at the hooves of her own new-born lamb...and far from the last.
The Emperor Melkarth was far away at the time but documents from attendants and those who heard from them afterwards tell of sordid things even from the moment before the creature that would shake the world drew his first breath.

Concubine Yantan-Tethera was not a true-blooded goat. She was a sheep. The sheep, or ‘Skith’ were a subordinate race in Gith, considered a non-magical subspecies of the goat. The two sibling races had begun their rise to power by warring with each other until all nearly all sheep in Gith were under the chattel of the goat, treated as all but slaves, paid less, fed less and essentially seen as less. Similar to the rift between unicorn and earth pony only much more violent and completely one-sided, the magic-using goats saw the sheep as lesser extensions of themselves, serfs or outsiders. The Skith were confined to ghettos or made their home in the mines, mills, foundries, workshops or servant quarters they worked in day and night.
Yantan-Tethera was a gift of conquest. It is all but confirmed she was the daughter of a rebel Skith leader that Emperor Melkarth had destroyed in a counter-rebellion but the name of the sheep leader is unknown.
[Note: There are some documents that suggest Melkarth subjugated at least two significant Skith rebellions close to the year Yantan-Tethera must have gotten pregnant; Tegtup Hoggerel the Uncastrate or Burhel Nayaur the Blue Storm. Of the two, Burhel is most often theorised to be the maternal grandfather of Grogar but information about him regarding the fact that he succeeded in slaying Melkarth’s beloved nephew, Shkerebin Serpent-Eater, suggests Burhel Nayaur’s kin were wiped out utterly and Emperor Melkarth taking a concubine of his blood would have been regarded as highly disrespectful to his nephew’s line. Burhel Nayaur is still celebrated by the northern sheep and regarded as a hero and a liberator and ovine scholars have denounced any idea that Grogar shared blood with him. Tegtup Hoggerel, however, was a palace slave who was due to be made a eunuch but escaped and sought revenge on the caprine by deflowering young goat girls, handmaidens and even concubines of Gith nobles. So it seems that if Yantan-Tethera was his daughter, she would have likely been born from a goat that Tegtup had raped and she is never stated to have been a hybrid in any record. What’s more, taking a female born of a goatmaid raped by a sheep would have been seen as just as disgusting as taking the daughter of one who had murdered your kin.
Regardless, Grogar’s maternal grandfather remains a mystery and perhaps the world feels safer for it.]
At the time of the birth, Melkarth was marrying his twenty-seventh wife, at least nineteen of his original wives still lived at the time and he already possessed a harem of just under two-hundred-and-fifty young concubines. Another child was pretty much a triviality for him, particularly one from a concubine, children of which would often grow up to take slightly-higher-than-middle-management positions in the Gith bureaucracy, military or divisional administration across the vast empire, largely doing nothing more than making the royal family look good. But even before the birth, there were signs this would be no triviality for either parent or for the empire.
Yantan-Tethera’s pregnancy had been unnaturally quick and shockingly painful. She ate very little yet her belly was swollen in mere weeks. Her wool was falling out in certain places and the silks she wore to cover it seemed to degrade, catching some odd grey mould that ate away the rich fabric. She would be found in the lavatories, bleeding from personal areas, cursing and crying and begging somecreature to ‘get the monster out of her!’. She suffered nearly constant nightmares and even hallucinated seeing the corpses of those she knew, among them Emperor Melkarth himself who she saw at random intervals being pursued and consumed by some mysterious entity which she couldn’t describe in words nor in illustrations but she assured witnesses the beast looked somehow ‘familiar'.

There are records from some of her attendants that speak of ill fortune borne from the moment the child was created which links to certain superstitions among the goatish races.
In traditional goatish culture, and certainly among the patriarchal Gith society, it is considered bad luck for the female to look upon the male during copulation. Sex and procreation is a very important and quite serious part of goatish culture and, for a goatmaid, to lay with a male is to give yourself to Paz, the goatish God of Creation, Nature, Masculinity and Sustenance, to breed with more than just a rutting goat but to be part of the goatish cycle of life, to be one with creation, to birth another goat as Paz birthed all goats from the conquered World Mother and her Thousand, Thousand Daughters.
[Note: Paz’s mythos has rather...colourful details. One of his prayers involves the line ‘He whose supreme member is the axle around which turns the Wheel of Life’. Apparently, this is how he is portrayed in statues. I have been asked by the Royal Academy not to mention where any such statues can be found in Equestria.]
Therefore, a female goat simply keeps her eyes to the ground during copulation and cannot look upon her lover until after he is finished inside her. This was an ancient custom held in particular relevance in Gith. One Emperor, Ortsurg the Discerner, was so committed to this practice that he had every wife and concubine he chose to lay with blinded before taking them.
So it is proposed that, for one reason or another, Yantan-Tethera lay eyes upon her Emperor during mating and saw him as he was, not a god or a ruler, but as a rutting goat, base and common. And this, it is said, will sow an unfilial seed, a child who will seek to destroy the father.
When Yantan-Tethera at last shrieked that the baby was coming ‘she could feel its horns’, attendants hurried to help her deliver.
But no amount of aid, medicine or birthing rituals saved Yantan-Tethera whose womb tore open at the culmination and she swiftly bled out, her last words according to one report simply a gasping, whimpering ‘Oh Gods....What...Is...That...Thing?’
Before her drained, bloody body lay her lamb. A lamb unlike any the attendants had ever seen, these goats and sheep who had born thousands of children from hundreds of mothers.
Collectively, according to numerous crossing reports and memoirs, they describe looking upon the new-born lamb as the most unsettling experience of their lives.

Its coat was blue. But this was, strangely, an unnatural colour. In Gith, day passed so quickly that the sky was almost always a hue of pink or orange before it was night and the sea the same colour. And this particular shade was a murky blue, not the blue of any metal or precious stone they dug up or traded in Gith.
To the Gith, this particular blue had unpleasant connotations. It was, to them, the colour of death, of rot, of a tomb, of the obscure and uncomfortable, of the unknown and foreboding.
Adding to this unnatural phenomenon, the lamb had horns. While it was not uncommon for a new-born male goat to be born with horns, it was unprecedented in sheep or sheep-hybrids to anyone’s knowledge at the time. What’s more, this lamb’s horns were apparently larger than any had ever seen on any new-born and may have been the reason why the mother died in such agony during the birthing. They were large enough to already curl slightly. There is one document that actually declares that the lamb’s horns were the shape of a fully-grown goat’s and near as large, huge for the child’s head and barbed wickedly, tearing the mother open coccyx to navel and creating such a horrific image as to imply the lamb had ‘charged’ out of her womb. But this is near impossible and also suspicious how such a thing doesn’t appear in any other text.
But most startling was how the new-born behaved.
It did not cry. It did not wave its limbs or reach out at anything or blink to adjust to the light.
It simply crawled out and lay on the blood-soaked sheets, looking up with eyes as red as the womb it had come out of, eying the startled attendants in a peculiar way that some describe as ‘disdainful, as if the lamb was disappointed at what it had found outside of its mother, as if the first living things it had ever seen were entirely insignificant and not worth acknowledging. This child’, they claimed ‘Had been born from death and so could not distinguish it from life’.
When Emperor Melkarth returned from his nuptials to gaze upon his new son, he was said to be just as unnerved for the lamb looked at him in a similar way that he had to the common servants who had delivered him.
And so his father gave him the name ‘Grogar’.
‘Grogar’ is based around the Gith’c term for ‘contradiction’ and often refers to their early concepts of undeath. With no clear classification, a ‘gbroxh’gkaurn’ is a creature neither living nor dead.
The theory that Grogar did not understand life or death or distinguish it is an interesting one but as Grogar’s life developed and his actions were more widely seen, it seems more likely he simply didn’t see any worth in either at all if it did not benefit him somehow.
Grogar had been born without heart or soul.
But he did, unfortunately for the world around him, retain a supremely brilliant mind.

Grogar grew up in the lower palace and was monitored closely. If Emperor Melkarth had any concerns or suspicions about the child, he did not share them with any but his closest advisors. To him, one odd child and a concubine dying in childbirth was a mere inconvenience and he had many of those as it was.
Melkarth is not considered a bad ruler by historians but the nature of rulership in Gith was strict and taciturn and the civilisation of Gith itself was built upon many concepts and customs modern Equestrians would find barbaric today. Close relationships with one’s wives and children were frowned upon, the society at the time placed much greater emphasis upon a ruler developing close relationships with his most capable ministers, generals or advisors so as to benefit the state. This Melkarth did, or at least did his best to do. Apart from his eldest son, Anzar, whom he was teaching chiefly in the ways of a ruler, he had very little contact with his many, many kids.
His children each had tutors, custodians, nurses, wet-nurses, entertainers and servants to satisfy their every need. And regarding Grogar, these attendants were meticulous in writing of just what sort of lamb he was and what sort of creature he was growing up to be. It is believed the one organising this research was a certain Kumis, a talented mental-physician and philosopher who served the Gith Royal Family capably and well. Kumis was deeply concerned at the young Grogar’s behaviour and tried for many years to reach out to him without success.
Or perhaps he in fact found success but discovered that to be worse than failure.
His documents provide a fascinating insight into the young mind that would become the world’s greatest threat.
In the royal nursery, nogoat ever saw him play with any of his half-brothers, half-sisters or cousins or even noticeably interact with them. Nor did they see him play with any toys or models or games available to him. Kumis wrote that little Grogar would most often simply avoid company, find a place where he could be by himself and simply...observe. As an experiment, Kumis had several medium-sized, cotton-padded climbing blocks moved into the nursery and placed the second-largest in the corner of the room.
From then on, every time the young ones were let into the nursery, Grogar would always climb the block in the corner in silence, sit upon the top of it and watch. He watched every little kid playing below him, arching his shoulders and tilting his head in a way that registered a feeling of superiority. And when some of them would climb the highest block in the centre of the room and play-act upon the top of it, Grogar would crouch, as if to avoid them noticing him, his ears pricked, his eyes wide and his brow furrowed, registering one or more standing above him, indicating not just anger but a sense of enmity, as if those who had climbed higher than him had spited him somehow, whether they even knew it or not.
He ate slowly and took little interest in what he was eating, judging the most bland fodder as no more or less enjoyable or interesting than the choicest treat. He went to sleep a lot later than the others though he made no sound. He would simply sit up in bed, occasionally look to those slumbering infants around him and simply contemplate. With those wide, unblinking, red eyes of his. When he did sleep, he did so also in complete silence, unmoving under his blankets, caring little for any comfort or lack of such.
Kumis was becoming fearful. He was certain there was something unnatural about the child and Grogar’s lack of care to life or living it was apparent and the physician was sure it would become something worse. He ordered the guard watching the beds of the infants doubled, picking out the ones with the best night-vision, certain that some night soon, they would see a young Grogar crawling over to the bed of another child and placing his little hooves over the child’s neck.
Yet that night never came.
Instead, something arose that was far more sinister.

When Grogar was three, one of his half-siblings, Kindur, around the same age as him, was playing with a rattle that flew out of his hoof and hit little Grogar in the shoulder, making him stumble. Grogar didn’t fall nor did he register any pain and when Kindur went to pick up his rattle, he apologised. But Kumis states that Grogar looked at him in a way that he’d never looked at anycreature before...
“It was similar to how he had observed those playing on the highest climbing block. But this time, it was more focussed, more direct. There was surprise in his glance, his eyes were wider and his brow arching. His nostrils were flared as he breathed heavily through them. His lips were curled and his jaw shifted behind his cheeks in a way that indicated his teeth were clenched behind his closed mouth. I knew the signs.
It was more than mere rage Grogar was feeling. There was a flicker, a merest spark, of fear.
Kindur had threatened him. It didn’t matter to him how or for what reason or even how true it was. His expression or posture didn’t change as little Kindur tottered over to pick up his rattle and said ‘Sorry, Grogar’ before tottering away.
All that mattered to Grogar was that Kindur had made him feel threatened.
But any fear he must have felt was nothing compared to mine. I was terrified. Until now, Grogar was unsettling enough in his calm moods. Now he had been given, or rather thought he had been given, a reason to no longer be calm.
Kindur had woken a terrible fiend.’
Kumis watched Grogar closely throughout the day, seeing nothing too out of the ordinary other than prolonged looks at Kindur. That night, the rattle that had hit Grogar was found in Kindur’s cradle. Kumis simply put it back in the nursery and ordered Kindur’s cradle watched closely. Yet the morning came with no damage done to the kid, Kindur awaking bright and cheerful, eager to continue playing. However, when they checked under his cradle, they saw a dead cockroach.
This was most anomalous. The nurseries were shielded with window-sets of silver and silk and anointed every morning and evening with scented oils and incense. Nocreature had seen a single unwanted animal in the building in over four-hundred years.
Grogar was watching intently and there and then, Kumis heard the three-year old lamb utter the first word he’d ever heard him speak, in a cold, calm murmur.
“Dead.”
In his memoirs, Kumis curses himself for not paying closest attention to just what Grogar was looking at when he said his first word for he felt certain that the young lamb was not referring to the cockroach.
Kumis watched Grogar as Grogar watched Kindur all throughout the day, his red eyes fixed, unblinking. Yet the day passed otherwise entirely ordinarily.
The next morning, Kumis entered with the matrons to gently wake the kids. Kumis headed immediately to check on Kindur who was awake, bright and cheerful as usual with no marks on him and nothing wrong with his bed-place.
As Kumis checked on Grogar, he saw nothing unusual, Grogar wasn’t looking at Kindur or anycreature with any great interest. Then, as Kumis turned to check on the others, he heard Grogar murmur again.
“Dead.”
It was then that one of the wet-nurses gave a cry of horror.
One of the kids was lying in his cradle with his eyes wide open and his little face twisted with pain, still and silent.
The kid was Bezkri. He was dead. Apparently having choked on dessert not properly chewed.
He had spent the day before happily playing with Kindur.
When the doctors examined the body, they found that Bezkri’s Pogaplum Pastry that he had eaten the dinner before had been laced with agbel, a weak cyanide compound that was commonly used as a muscle relaxant in Gith and later in Equestria before falling out of fashion thanks to his obvious health risk. Testing it, the doctors found that the agbel had been dehydrated to a much more toxic wet-powder that had been hidden in the dessert, a slightly soapy-tasting substance that would have mostly gone unnoticed thanks to the Pogaplum Pastry’s sweetness. The cyanide killed the kid and, measuring the dehydrated agbel, Kumis deduced Bezkri ingested around four spoonfuls of the substance.
It was then that Kumis heard that same cold, calm murmur just behind him.
“Three.”

Kumis writes vaguely of this moment in his writings. Hearing the voice, he turned suddenly behind him where he swears on his soul he saw little Grogar standing just outside of the slightly ajar door.
When he demanded to know what Grogar meant by that, his colleagues asked him who he was talking to.
Kumis turned to the door again and saw that Grogar wasn’t there anymore if he had been earlier.
Kumis assures himself in his documents that, based on where each creature in the room was positioned, only he could have seen Grogar from where he was standing. But the fact that nocreature heard him either made him terrified, particularly as, measuring the agbel again, it was indeed three spoonfuls.
However, Bezkri’s death was looked into by the palace attendants and personal guard of the royal heirs, the Makapan, conducted an investigation and produced the culprit; an unstable kitchen-servant whose son had recently died of malnutrition and considered it monstrous how the Emperor’s kids could stuff themselves with treats every day while those below starved. It had appeared that Kumis was mistaken about Grogar being directly responsible for Bezkri’s death. However, if Kumis had heard what he had indeed heard, Grogar still knew of the exact circumstances around the murder. By what means was uncertain.
At the age of three, he had become complicit in the murder of one of his half-siblings. By what means, Kumis could not determine, but he was absolutely certain.
More suspicious deaths followed. At this time, infant mortality, even among the royals, was still quite frequent, but the way in which kids would die, all strange ways at strange times, made Kumis ever more terrified. Kindur remained alive yet he grew increasingly troubled by Bezkri’s death and that of others and the effect it had on him resulted in depression where he simply stopped enjoying anything. He’d rarely leave his bed and when he did, he’d never take part in any activities. Kumis, for a while, observed him and, more importantly, observed Grogar’s reactions to him.
Yet there were none. Grogar took no interest in the half-sibling who he believed had wronged him and simply went ahead with doing what he always did, sitting on the climbing-block in the corner and looking down on everygoat.
One day however, when Grogar was nearly five, there was something particularly unpleasant. A half-sister of Grogar’s, Ypsla, once offered to let Grogar play with her and her companions and called her by the name ‘Groggy’. At this, Grogar slowly fixed her with a look of contempt and replied coldly.
“Grogar. You will call me Grogar.”
When Ypsla said ‘Groggy’ sounded more fun, Grogar said nothing but simply cast her a look of even worse disdain. Kumis is certain he saw burning hatred behind those red eyes.
When it was time for lunch, Grogar climbed down off his block and was met by Ypsla calling him ‘Groggy-Woggy’ over and over. When Grogar responded flatly that that was not his name, Ypsla stuck her tongue out at him and walked away.
Kumis had Ypsla watched and guarded closely along with those she was playing with at the time.
The next day passed with nothing out of the ordinary until, Kumis documents, Ypsla approached him with her tongue out. Kumis gently but firmly told her not to stick her tongue out at him.
Then it fell to the floor.
Kumis stared at the perfectly removed tongue that had simply dropped like an overripe fruit from Ypsla’s mouth. Soon, the other kids in the room saw it too.
Then the screams began.

Ypsla was hurried, screaming and sobbing incomprehensibly, to the hospital wing of the palace. Her mouth was examined and the doctors determined her tongue had been magically removed. Kumis declared that was impossible as the Makapan were trained to sense magic and the nursery was guarded by wards just before the doorway. A warlock was brought in and she determined that the spell that had removed Ypsla’s tongue had an intentional delayed reaction so the spell was cast almost a day before it went into effect.
At this, Kumis documents his theory. Grogar cast this spell as soon as the kids passed under the doorway to the dining room, a brief gap where magic could feasibly be cast. Useless for any assailant, one would have to get past all manner of guards and defensive measures at every entrance and exit but entirely possible for one already in the nursery.
Kumis deduced that Grogar had cast the spell as he and Ypsla stood in the doorway yesterday. But Grogar had been taught very little magic, certainly not a spell of this magnitude and horrific capability.
Kumis was left with only one possibility, Grogar was simply gifted. And he was learning to use his gifts to hurt those who did anything to offend him. Purely on a whim.
The delayed tongue-removal spell was one which few adults could master and the fact that Grogar had discovered how to bypass measures to protect his siblings, all on his own, made it even worse.
Kumis was left with only one option. Informing the Emperor confidentially of the dangers of his son.
Predictably, Melkarth believed Kumis was losing his mind and told him to go on a leave of illness until such a time as he deemed him fit for work. Kumis was not harmed but he was dragged out and warned not to press as he cried out for his Emperor to protect his children from this deranged lamb.

Other tutors took over monitoring Grogar and some of them earnestly spoke well of him. Yet they confessed to being confused by his general attitude to life.
One rather mundane but very important point the tutors discovered was that Grogar was exceptionally talented in just about anything. Princes were taught every royal art and craft from hunting to swordwork to archery to music and dance to painting to foreign languages to sciences to every subject known to traditional education. He excelled in each one days into his first lesson, impressing every teacher one after the other, producing work goats three times his age could not fathom.
Yet after excelling and being convinced he had excelled, he lost interest in the subject entirely, not wishing to speak of such a thing for the remainder of his tutelage, dismissing any thought of pursuing it as an interest or hobby as ‘meaningless’ and any wish for others to see him do so was met with curt dismissal.
In all their years, his tutors had never seen a child who was so adept at life in general yet took so little interest in it.
There was one important skill he still could not master however and that was social interaction.
For seven years, Kumis spent his time at home, trying to recover with his family and wondering if he had truly been correct in suspecting so many unfortunate things as Grogar’s doing.
However, one evening, he was sent a gift, a small box wrapped in cotton. Looking startlingly like the cotton boxes he bought for the kids to test how Grogar reacted.
He took it to his study and opened it to find it filled with dead cockroaches.
The letter was marked by a severed tongue, one he knew to be that of a crocodile (Crocodile tongues being a common alchemical ingredient in Gith) but the meaning behind it was clear as was its sender.
In his documents he states that as he stared at the contents of the box, something flew through his open window; A kid’s rattle.
He looked out the window and stared at a ten-year old Grogar staring at him all the way from the balcony of the palace nursery. With a truly unsettling smirk on his face.
Kumis noticed guards were swarming and he heard from them that Prince Kindur had committed suicide, jumping from the balcony to his death.
Fearfully, he returned to his study and read the letter. It was expertly written and perfectly courteous.

‘Hello again, my dear doctor.
I do miss you, I hope you know that.
I am earnestly grateful for the interest you always showed in me.
And I feel I should inform you that I have taken a similar interest in you. And those close to you.
As your, for lack of a better word, student, I feel I should inform you that my majestic father has determined me of age to move outside this palace.
I understand that neither of us have been entirely well but I am sure we can both find out so much more about each other now.
I have a lot of interesting tests in mind for you.
I look forward to seeing you very soon.
Sincerely.
‘A Little Contradiction’

Kumis writes of being more terrified than he ever had been in his life, even having been in Gongros during three sieges and an earthquake.
Grogar was coming for him.
Kumis and his family left the city two days afterward. He didn’t document anything during this time, fearing he’d lose a page and that Grogar would pick it up and follow him.
Unfortunately for the good physician, Grogar had no need. By what means are uncertain but Grogar knew where Kumis was.
This was still part of his test. Whatever Kumis feared Grogar would use to torture him, the sad truth was that Grogar had already begun his torture.
Using nothing but the fear that the old goat had for him.
And fear would be his most deadly weapon throughout his rise to power.

7470182

Jesus, your Grogar is creepy. Like the worst aspects of every “Kid Antichrist” character in Biblical Apocalypse fiction rolled into one. I also got some Micheal Myers and Dr. Loomis vibes from the relationship between Grogar and Kumis.

7470498
Thank you very much.
Yeah, there’s no Freudian Excuse behind this kid. He’s not making a cry for help, he’s causing it!
Yes, Kumis was a Loomis reference. Michael Myers was an inspiration for Grogar and other depictions of child psychopaths.

7470524
I also had some inklings of Damien from The Omen, which I also feel was intentional?

7470532
I uh...I haven't actually seen that film so I'll have to take your word for it.