Wilson, Brewster, and Koko's Adventures of Pokémon 3: The Movie

Wilson, Brewster, and Koko's Adventures of Pokémon 3: The Movie is the third upcoming Chuggington/Pokémon crossover to be made by Stuingtion. And is the sequel to Wilson, Brewster, and Koko's Adventures of Pokémon: The Movie 2000.

Plot
The feature film focuses on the beautiful town of Greenfield. A resident of the town, the research scientist Professor Spencer Hale, conducts research on the elusive Unown. He and his assistant, Skyler, discover a site of ruins, but Hale is sucked into the dimension of the Unown.

His disappearance leaves his young daughter Molly alone, her mother having disappeared previously. Molly finds a box of tablets containing Unown images and begins assembling the letters, which summons the Unown themselves. The Unown use their powers to make Molly's wishes come true, transforming her manor house into a crystal-like palace which spreads across the town and cuts her off from the world. Entei is created to represent Molly's father. Various people come to help sort out the Unown, including Professor Oak and Delia Ketchum (Ash's mother).

Meanwhile, Ash and his friends meet and befriend a trainer named Lisa. They come into Greenfield in the process and agree to join in the rescue mission to save young Molly. However, Entei kidnaps Delia, following Molly's request for a mother as well. Entei's powers hypnotize Delia into thinking she is Molly's mother. Ash, Misty, Brock and their Pokémon head out to the mansion to save Delia, communicating with Professor Oak and Skyler thanks to a PokéGear device given to them by Lisa. Team Rocket try to investigate the mansion, only to be blasted out of the air by Entei into the depths of the mansion. Molly watches Ash's Bulbasaur and Chikorita in action through a television and falls asleep, imagining herself being a Pokémon Trainer. Seeing Ash on TV, Delia snaps out of her trance, which is not noticed by Entei, who then creates a dream version of Molly as an adult and takes her to battle the three. Molly first fights Brock, but Molly's dreamed-up Pokémon are stronger than his; Molly then has a more friendly fight against Misty in an underwater battle, but the winner is not shown.

Ash manages to locate Molly and Delia, but Molly refuses to leave with him and the mansion transforms. Entei refuses to allow Ash to leave with his mother, and fights his Pokémon. Entei defeats Totodile and Cyndaquil with ease, and battles Pikachu. He then blasts Ash and Pikachu off a cliff, but they are saved by the arrival of Ash's Charizard. Charizard, with Ash on his back, battles Entei until he is knocked out of the sky. Entei nearly kills Charizard until Molly commands him to stop and begs that no more fighting happens, which manages to stop Entei. Ash and his friends convince Molly to leave with them, Entei revealing he was created by the Unown to be her father.

The Unown suddenly lose control of their powers and start to seal the group in the mansion. Ash, Pikachu, Charizard, Misty, Brock, Delia, Molly and Team Rocket escape down to the hall where the Unown are. Pikachu and Charizard attempt to break the forcefield protecting the Unown, but they are unsuccessful—until they are joined by Entei, combining their powers to destroy the shield with Molly's support. Entei sacrifices himself and the Unown return to their dimension, reversing all of their effects on the world and returning Professor Hale to the ruins where he originally vanished.

The group ventures outside, where Professor Oak, Skyler, Lisa and others meet them. Team Rocket hides in the mansion upon seeing all of the police outside and declare that they will always have another opportunity to catch Pokémon. In the end credits, Charizard and Lisa depart from Ash's company; Molly is seen with her own Teddiursa and reunites with her father—and later, with her long-lost mother.

Trivia

 * guest star in this film.
 * The storyline continues in Wilson, Brewster, and Koko's Adventures of Pokémon 4Ever.