When a human from a world with giant robots and snake terrorists gets transported to Equestria during episode one, he accidentally changes a critical point in history which causes an alternate timeline.

Follow him as he tries to find a way back home while trying to stop evil in a world where the Elements of Harmony are still dormant.

After Mikey got his scar from Jagwar and quitted the team, he traveled to a dimension where humans and humanoid animals lived. He reunites with Napolian Bona-frog and becomes a music star. He then meets a female humanoid lizard who is a music star too, she'll be Mikey's next love. Then his new ninjitsu'ish and superpowerful journey begins with the Young Six, The Rock "N" Beats, and teenagers with super ninjitsu powers. And they also meet...The Transformers, who came to their dimension to find pieces of the allspark and put a stop to Megatron and the Decepticons.

when Sunset Shimmer applies for a job as a Night Guard for the Canterlot Mall, she soon discovers tiny robots in disguise live inside the mall, hiding as anything, objects, technology, even food! Now she becomes friends with a group known as The Lost Bots and helps to keep the Botbots existence a secret.

Sunset Shimmer owned by Hasbro, Transformers Botbots also owned by Hasbro, story based on the Botbots Netflix series

200 Years ago Sunsets shimmers family found a mysterious object and shocked them and they went insane, Sunset was questionable about this until she find a note saying a curse will happen in the year 2017, Confused she tells her friends but what she doesn't know that it would happen sooner then she thought

the story that Inspired this -> https://www.fimfiction.net/story/286612/transformers-equestria-girls

On Cybertron, there remain few cybertronian lifeforms. One of which is Shockwave; the computer on legs. Thanks to a mission to intercept the ark going wrong with an unstable space bridge caused by Grimlock and the successful test subjects Swoop and Slug. Shockwave as deemed Megatron as well as the rest of the Decepticon Army aboard either the Ark or Nemesis KIA, until further notice. Until then, the scientist has his optic set on another primitive planet rich with raw energy; the only con is its teeming with lifeforms. One of which must be exterminated entirely. Who better to send than the slayer of bugs himself along with Slug and Swoop.

Taylor trap in the locker called out for help, ends up summoning Hasbro heroes. Now the world of Worm now have some old fashion heroes to save the day.

Twilight goes out for a walk when the Changelings attack, Twilight along with Spike and Starlight were the only ones to make it to safety but just before the Changelings could find her, a yellow car and a green jeep appear out a portal and the motorbike and jeep transformed into robots before blasting the changelings out the sky. the door to the yellow car opened to reveal Sunset Shimmer in the drivers seat. After escaping Equestria, Twilight, Spike and Starlight meets the team she will be working with to save hers and and the others homes, Optimus Prime, Deku, Ladybug, Freddy Fazbear, Steven Universe, Sonic the Hedgehog, Mario and Sunset. Meanwhile on a giant spaceship known as the Nemesis, An evil being hatches a plan to take over the universe and multiverse.

Background: set in an MLP/Transformers comic world. (References what happened to Megatron at the end of the fan comic "Tranformers vs My Little Pony" by kitfox-crimson on DeviantArt.)
Deceptions are now coming after Alicorn magic as well as unicorn magic. Autobots have set Ponyville as their center.

Summary: Starscream decides to go undercover in Ponyville to find out about the Autobot's plans. But, he meets and falls in love with a curtain purple, reformed unicorn.
(Also Published on FanFiction by me!)

Can the Avengers, the Autobots, Discord and his family; stop the first Decepticon from stealing all six infinity stones. Before he snaps his fingers and Half of reality is wiped out.

An alien cyborg has come to Earth and has started incinerating humans seemingly at random and for no known motive. Sunset Shimmer and her friends decide that they have to deal with their first alien threat in an adventure where the fate of the world could be at stake.

But perhaps Rom the Spaceknight is not the alien threat that they should be worried about?

Transformers was the closest franchise to fit into the category.