Little Bear's Adventures of My Little Pony: The Movie

Little Bear's Adventures of My Little Pony: The Movie is an upcoming Little Bear/Lionsgate crossover to be made by Hiatt Grey.

Plot
The ponies of Equestria prepare for their first Friendship Festival, which is overseen by Princess Twilight Sparkle in Canterlot. The festivities are interrupted by an invasion of monsters commanded by the broken-horned unicorn Tempest Shadow, who uses magical obsidian orbs to petrify Twilight's fellow princesses; Princess Celestia unsuccessfully urges Princess Luna to seek help from "the queen of the hippo" before being interrupted. Twilight flees the city alongside her five pony friends – Pinkie Pie, Rainbow Dash, Rarity, Applejack, and Fluttershy – and her assistant dragon, Spike. Tempest gives pursuit under orders from her superior, the Storm King, to gather all of Equestria's princesses for him to harness their magic through his mystical staff, with the promise of having her horn restored in exchange.

Twilight's group travel to the desert city of Klugetown in search of the aforementioned "hippos". A feline con artist named Capper offers to escort the group, secretly intending to sell them to settle a debt. However, he develops a genuine friendship with them after Rarity generously mends his coat. Twilight discovers an atlas that reveals the "hippos" to be hippogriffs, exposing Capper's treachery. After the group evade Tempest aboard a delivery airship, Tempest brings Capper to guide her to them, but he deliberately misdirects her to atone for deceiving the group.

The airship's birdlike Captain Celaeno and her crew reluctantly allow the group passage during a lunch break, revealing themselves to be former pirates that have been forced into the Storm King's service. Rainbow Dash persuades the pirates to defy orders and take her group to the hippogriffs' kingdom on Mount Aris. In celebration, she performs a Sonic Rainboom that inadvertently gives their location away to Tempest, forcing the group to escape in a makeshift hot air balloon before Tempest destroys the ship with the pirates and Capper on board.

The group reach Mount Aris to find it deserted. They explore the ruins and become trapped in an underwater cavern, where they are saved from drowning by the seapony Princess Skystar and led to her undersea home of Seaquestria. Skystar identifies her kind as the hippogriffs, transformed by a magic pearl used by her mother, Queen Novo, to hide from the Storm King; Novo demonstrates by turning the ponies into seaponies and Spike into a pufferfish. When Novo denies them the pearl to use against the Storm King, Twilight desperately attempts to steal it while letting her friends unknowingly distract the seaponies. Pinkie Pie nearly changes Novo's mind until Twilight is caught, prompting the outraged queen to banish the entire group to the surface.

Abandoned by her friends over her actions, Twilight is abducted by Tempest and brought before the Storm King in Canterlot to have her magic absorbed; Tempest gains Twilight's sympathy when she divulges how she lost her horn in a monster attack as a filly, which caused her own friends to shun her for her dangerously unstable magic. Meanwhile, after Spike alerts Twilight's friends to her capture, Capper, the pirates, and the hippogriff Skystar return to help them infiltrate Canterlot and mount a rescue. The Storm King retaliates by conjuring a tornado in the city with his newly empowered staff, betraying Tempest as well. Twilight saves Tempest from the tornado and reconciles with her friends, successfully working together with them to take the staff. The Storm King hurls an obsidian orb at the group to reclaim the staff, but Tempest jumps in his way, petrifying them both. The Storm King's body falls and shatters, while the group use the staff's magic to revive Tempest, who returns the stolen magic to restore the princesses and repair the damaged city.

The Friendship Festival resumes, and the ponies celebrate with all of the allies Twilight's group have made on their adventure. Tempest is disheartened by her still broken horn until she is convinced by Twilight to join the party by producing a fireworks display with her magic, happily accepting the group's friendship.

Trivia

 * Team Griffin/Eeveelution, The Griffin Family, Vinny Griffin, Glenn Quagmire, Cleveland Brown, Joe Swanson, Mother Bear, Father Bear, Grandfather Bear, Grandmother Bear, Rusty Bear, Granny, No Feet, Tutu, Doug Funnie, and Skeeter Valentine guest star in this film.
 * Tutu and Twilight Sparkle are both voiced by Tara Strong.