The Equestria Girls Meet Captain Underpants (titled as The Equestria Girls Meet Captain Underpants: The First Epic Movie) is an animated comedy spin-off based on the DreamWorks Animation film, Captain Underpants: The First Epic Movie, which is based off the book series. It is being co-written and directed by Daniel Lawrence while it being written by Jose Ramirez and Andrew St. Germain. The film is being developed by D-L Productions, KirbyStar Studios, and B-Master Animation while being distributed by Universal Pictures.
The Equestria Girls go to Piqua, Ohio, where they meet two prankster kids named George and Harold. When their mean principal, Mr. Krupp, threatens to put them in separate classes, they hypnotize him into thinking he's Captain Underpants, a superhero from their comic books. But with Professor Poopypants threatening to get rid of laughter forever, they must save the world and put an end to his evil plan.
The Rainbooms: Twilight Sparkle, Fluttershy, Applejack, Rarity, Rainbow Dash, Pinkie Pie, Sunset Shimmer & Spike
- The music will be from Theodore Sharpio and William Anderson while the additional music will be from John Debney and Lorne Balfe
- This is the third time for KirbyStar and B-Master to collaborate with Daniel Lawrence after The Powerpuff Girls' Smurf Trilogy and Ed, Edd n Eddy: Scammers in Time.
- This is also B-Master Animation's first film that focuses on the Equestira Girls.