Is he a seventh element of harmony? A dimensional traveler like Pinkie thought? A cyborg Azalea from the future? Post your theories about the Trilogy's best-realized and most important character right here.

Clearly Home Run was a lonely, misunderstood ex-marine brony who wished to be reborn in Equestria. He made it his sacred duty to protect his Waifu Twilight in the hopes that she would love him forever and keep him by her side.
You can see how well that worked for him... He's done that like a billion times now.

He is a being older than Equestria.

Older than the Elements.

Older than time.

Always watching.

Always waiting.

And he will strike down the non-believers in his wrath.

Praise be to Home Run.

The seventh element of harmony, Grievous Bodily Harm?

I think it's more likely that Home Run is the equivalent of the element of magic, only for violence. "There are six elements of violence, but only five are known: Fear. Pain. Despair. Anger. Righteousness. When all five are present, a spark will cause the sixth to appear: the element of Weaponry"

Okay, let me finish chuckling...
Home Run is more than a tool to discipline Changelings, he became a friend. Friends don't abandon each other, and Friendship is Magic. Along with loving and tolerating the shit outta them.
I'm still waiting for Twi to do the Babe Hoof point over the fence thing before sending a Changeling out of the park...

Twilight turns around and see's Home Run walking by like those magic brooms in The sorcerers Apprentice, waving.

1193676
I think it was just a regular bat until Twilight enchanted it off-screen.

Trapped in a time loop for 65 million years, Home Run was a plank of wood that evolved into the upstart, devil-may-care scallywag we all know and love.

1193705
1193708
1193717
1193723
1193739
1193794
Or it's just a regular bat.

1193895 Blasphemy.

1193895 What?

1193895
What fun would that be?

1193717
Great, now I have to figure out what the rest of the Regalia/Bearers of Violence are. Going in the listed order, we have...
Fear: Fluttershy's foothoofball helmet from "Dragonshy."
Pain: One of Pinkie's inanimate party guests. My money's on Rocky.
Despair: Rarity's fainting couch, naturally.
Anger: Either Bucky McGillicuddy or Kicks McGee.
Righteousness: The Sonic Rainboom.

Home Run exits atemporally, it's the universal constant of head injury.

1193895 If it's just a regular bat, explain how it reappeared in Twilight's house after she lost it in the alternate timeline.

Calling it now, Home Run is a changeling.

Home Run was originally a pony that really, really pissed Twilight off in the middle of a time loop by running up to her and shouting that she should just "beat the changelings up, or something."

It's pretty clear he's no longer a pony.

The more important question, I think, is why I haven't seen any saucy ponified Home Run art yet.

1193911
That awkward moment when I'm Jewish.

I was thinking something like

Once upon a time, there was a seed.
Not just any seed, mind you, but a true seed, born of light and darkness, dreams and realities, space and time.
This seed fell into the hands of a child. The child planted the seed, not knowing how special this seed was.
Everyday the child watered the seed, which eventually grew into a sapling. The child was happy at the plant's growth, as was the plant itself.
Time passed, and the child and the tree grew. The child visited the tree less and less, the tree relying on the rain to grow, and not the gifts brought by the child.
Then one day the child stopped coming altogether.
The tree sat patiently, as trees are wont to do. It grew mighty and large in its friends absence, reaching for the sky.
It had been growing for a long time, how long the tree didn't know, when it heard the sound of a child's laughter. Had their friend returned?
No. This was not their friend. The small child which climbed their branches didn't carry the same soul. The larger one nearby was familiar- the tree's friend had grown up without it, and now this new child has taken their place.
So years went on, and the tree was happy with this new gift of a friend from a friend. It did everything it could- within its own tree-like limitations- to keep them happy in return.
But something wasn't right. One of its branches felt strange, similar to how its leaves and twigs feel when... Oh.
The branch that fell during the night was discovered by the young boy who had claimed the tree as his hangout. He told his father about it, who then took the branch into his workshop, stating he had an idea.
When he came back out, in his hands was a finely carved baseball bat. The little boy's eyes lit up, and he went to find some friends to try it out in a game.
He only got to use it for one day before a habit of the universe struck. A hole through time and space, one of many which misplaces items (socks in particular), placed it into another universe, one populated mostly by equines.
Now the bat, once being part of the tree born of a true seed, found this a peculiar circumstance. It grew even stranger once the time loops began.
As a bat that was part of a tree born of a true seed- otherwise known as a true bat; the one true bat if there are no others- it knew something was amiss. All this screaming which would start and stop and then start again exactly the same way as before... It wished it could help.
Then she came. Home Run got a name, a chance, a way to help. If they were separated, Home Run need only wait, and he would find her. Because he was a tree, and he was good.

- The Written Log of Princess Sparkle (Loop #34456)

If you actually read this, I am shocked at how bored you are. But then, I'm the one who wrote it, so that makes me worse. xD

1219918
Oh my god that was perfect.

Home Run is the Time Loop universe's equivalent of Plank from Ed, Edd, and Eddy.

Is this what Home Run looks like?