Thea Sharrock, director of the tearjerker Me Before You, is helming the live-action/CG hybrid, which has a script by Mike White and has Angelina Jolie on board as a producing as well as voicing one of the lead characters.

Published by HarperCollins in 2011, the book centers on a silverback gorilla named Ivan who lives in a cage in a shopping mall along with an elephant named Stella (Jolie) and a stray dog called Bob. Ivan does not remember life before the mall, but when a baby elephant named Ruby enters and Ivan finds himself taking care of her, he begins to rediscover his previous life and concocts a plan to take the baby elephant away from their abusive owner.

Rockwell will voice the title character of Ivan the gorilla.

Brooklynn Prince, the breakout lead of acclaimed indie drama The Florida Project, is already cast as the voice of Ruby.

Ariana Greenblatt, one of the stars of Disney Channel's Stuck in the Middle, is playing the lead, making up the live-action portion of the project.

Brigham Taylor is producing the movie with Jolie. Allison Shearmur, who recently passed away, will retain a producer credit on the movie.

Rockwell's turn as a racist police officer in Three Billboards has generated much acclaim, alongside the movie's trajectory. So far this awards season he has won a Golden Globe, a BAFTA and a SAG Award, among numerous others, for his performance.

He recently wrapped Adam McKay's untitled biopic of former vice president Dick Cheney in which he stars opposite Christian Bale and portrays President George W. Bush.

Rockwell is repped by Gersh and Untitled Entertainment.