On January 14, 2015, Matthew McConaughey was cast in the film's lead voice role.[3] Chris Meledandri and Janet Healy produced the film.[3] On June 17, 2015, it was confirmed that McConaughey's character is named Buster and that John C. Reilly would voice Eddie, a black sheep and Buster's best friend.[7] In November 2015, it was announced that Reese Witherspoon, Seth MacFarlane, Scarlett Johansson, Tori Kelly, and Taron Egerton had joined the cast of the film.[6]