“Partysaurus Rex” is a short animated film in the “Toy Story Toons” series, produced by Pixar Animation Studios and released in 2012.

The story follows Rex, the green toy dinosaur from the “Toy Story” franchise, who is left alone in the bathroom to entertain himself while Bonnie, his new owner, takes a bath. In an attempt to fit in with Bonnie’s other toys, who are all aquatic-themed bath toys, Rex starts to experiment with the water and accidentally causes a giant bubble to form.

To his surprise, the bubble turns out to be a party animal named “Bathos,” who quickly teaches Rex how to have fun and throw an epic bath party. The party includes disco lights, a bubble machine, and dancing to electronic music.

However, things start to go wrong when the bathwater starts to overflow and flood Bonnie’s house. The other toys help Rex clean up the mess, and in the end, they all come together to have a fun time at the party.

“Partysaurus Rex” was directed by Mark Walsh and features the voices of Wallace Shawn as Rex and Corey Burton as Bathos. The film was included as a bonus feature on the home media release of “Finding Nemo 3D.”