This weekend, Disney held it an expo for its D23 official fan club. The event was filled with celebrities and tons of news about upcoming Disney projects. Of particular interest is a brand new movie project being planned by Pixar.

The Good Dinosaur is an alternate-history tale of dinosaurs in a world where their extinction never took place. A specific dinosaur named Arlo, a teenage Apatosaurus, will be the main character of the movie. Arlo will be accompanied on his journey by a human boy named Spot.

The Good Dinosaur is scheduled to release on May 30, 2014. Disney was confident enough in the project to go ahead and reveal its voice cast at the D23 Expo. Lucas Neff, best known as Jimmy Chance from the Fox TV series Raising Hope, will be voicing Arlo. Neff appeared on-stage at D23, joining Bill Hader (of SNL fame) and Judy Greer (Kitty Sanchez from Arrested Development), who will be voicing characters named Forrest and Ivy, respectively. Other voice cast members include John Lithgow and Frances McDormand as the voices of Poppa and Momma, as well as Neil Patrick Harris as the voice of a character named Cliff.

The movie’s story is still being kept secret, though Disney did state that Arlo will be setting out on a “quest to restore peace” after a “traumatic event” upsets his home life. Bob Peterson, the co-director of Up is co-directing The Good Dinosaur with Pixar animator Peter Sohn. Peterson is also credited with writing the movie’s story, along with animator Enrico Casarosa.