Thomas' Adventures of My Little Pony Equestria Girls is an upcoming Thomas & Friends/MLP:EG Crossover film to be created by 76859Thomas. It will appear on Google Drive as a double feature with Thomas' Adventures of My Little Pony: Friendship is Magic - Magical Mystery Cure in the near future.
Set after the events of "Thomas' Adventures of My Little Pony: Friendship is Magic - Magical Mystery Cure", in Equestria, the newly crowned Princess Twilight Sparkle visits the Crystal Empire with her Ponyville friends for a royal summit with Princess Celestia, Luna, and Cadance. That night, Twilight's crown and Element of Magic is stolen by the unicorn Sunset Shimmer, a former student of Celestia. After a chase through the castle, Sunset drops the crown through a magic mirror and follows after it. The princesses inform the ponies that the mirror leads to a different world, and task Twilight with retrieving her crown on the other side before the portal closes again for thirty moons, or else the Elements of Harmony borne by her friends will no longer protect Equestria. Despite Celestia's insistence that Twilight must travel alone, Twilight's dragon assistant Spike anxiously jumps in after her as she enters the mirror.
In the other world, Twilight and Spike are transformed into a teenage human girl and dog, respectively. While struggling to adjust to her new body, Twilight investigates the nearby Canterlot High School where she encounters several human students and faculty members resembling ponies in Equestria, including her friends Applejack, Fluttershy, Pinkie Pie, Rarity, and Rainbow Dash. She befriends the five girls, helping to bridge the animosity that Sunset had created between them in the years prior to Twilight's arrival. Twilight discovers that Fluttershy found the crown and gave it to Celestia, the school principal, who mistakes it for a prop meant for the elected Princess of the upcoming Fall Formal. Twilight decides to run for Fall Formal Princess against Sunset to retrieve the crown. Sunset tries sabotaging Twilight's campaign first by uploading a humiliating online video of Twilight behaving like a pony, and later framing her for wrecking the formal decorations in the school gymnasium. However, Twilight's new friends, including Sunset's ex-boyfriend Flash Sentry, help counter these ploys and improve Twilight's popularity among the students.
Shortly before the start of the Fall Formal, Rarity finishes getting dressed and putting on her makeup. She offers to put makeup on Applejack as well, but she declines. After some encouragement from her friends, Applejack hesitantly agrees. When Rarity finishes, Applejack is not too thrilled with the results and asks Rarity to wipe some of the makeup off. In the end, Applejack looks exactly the same as before Rarity started, much to Rarity's chagrin.
At the formal, Photo Finish is employed as the dance photographer. After taking a picture of the Cutie Mark Crusaders, she is unsatisfied with the photo. When the Equestria Girls pose for their photo, Photo Finish suggests adding some style, with assistance from Pixel Pizzaz. The girls take pictures in various costumes and accessories, including Sherlock Holmes-inspired looks for Princess Twilight and Pinkie Pie and queen and butterfly looks for Rarity—all while Rainbow Dash and Applejack play pranks in the background. However, during one of the photos, Rarity's butterfly wings briefly catch fire. When they finish, Photo Finish declares this the pinnacle of her photography career and makes her trademark exit. As the girls laugh, Rarity asks if she can keep the wings.
As the Fall Formal continues, a country-western song that Applejack requested earlier starts to play. Applejack invites her little sister Apple Bloom to join in a line dance with her. Seeing their dancing as a competition challenge, Rainbow Dash invites Scootaloo to join her on the dance floor in a hip-hop breakdance. As the dance-off becomes aggressive and Applejack and Rainbow get carried away, Apple Bloom and Scootaloo separate from them. At Apple Bloom's suggestion, she and Scootaloo start their own dance routine, winning the dance-off and receiving a trophy from Pinkie. Applejack and Rainbow look disappointed in the Crusaders at first, but they compliment the two on their dancing, and Rainbow Dash asks for a rematch.
Later, Twilight wins the election and the crown, but Sunset steals it after threatening to destroy the portal to Equestria. Upon donning the crown, Sunset transforms into a demonic creature and uses her newfound powers to brainwash much of the student body into becoming her army with which to invade Equestria. When Sunset attacks Twilight, her friends race to save her, evoking the crown's magic that protects them and temporarily gives them pony-like attributes. The magic of their friendship reverts Sunset to her human form and breaks her spell on the other students. Sunset becomes repentant, and Twilight asks her friends to look after Sunset in her absence. Twilight spends time celebrating with her friends at the formal before she and Spike take the crown through the portal, which closes behind them. Twilight and Spike return to Equestria, transforming back to their original forms on arrival and reuniting with their Ponyville friends.
- Ash Ketchum, Pikachu, Misty, Togepi, Brock, Jean-Bob, Speed, Puffin, Mushu and Cri-Kee are guest starring in this film.
- Both Thomas & Friends: King of the Railway and My Little Pony Equestria Girls were released in 2013 as well as the first twenty episodes of Thomas & Friends Series 17 were on air on Channel 5 and My Little Pony Friendship is Magic Season 4 were air on the Hub.
- This film will be extended with 3 Equestria Girls - Summershots (Make Up Shake Up, A Photo Booth Story and Raise This Roof which takes place during the real film.
- Thomas and his friends will see Sunset Shimmer and the Human Mane 5 again in Pooh's Adventures of My Little Pony: Equestria Girls - Rainbow Rocks.