Danny DeVito, Sylvester Stallone join 'Animal Crackers' LOS ANGELES, Nov. 7 (UPI) -- Danny DeVito has joined the cast of new animated feature Animal Crackers. The 69-year-old actor will lend his voice to the film alongside Ian McKellen and Sylvester Stallone. Patrick Warburton, Gilbert Gottfried, Raven-Symoné, Harvey Fierstein, James Arnold Taylor, Tara Strong and Lydia Taylor also provide voice credits. Scott Christian Sava and Tony Bancroft will direct, with Sava and Dean Lorey as writers. Sava will also produce with Jamie Thomason, Leiming Guan and George Lee and Marcus Englefield of Storyoscopic Films. Animal Crackers follows a family who inherit a rundown circus and box of animal crackers. The characters' lives are turned upside down when they discover the mysterious box of snack food turns people into the type of animal they ate. DeVito will return as Frank Reynolds on FX series It's Always Sunny in Philadelphia in 2015. The actor is also scheduled for Triplets, while Stallone will next appear in Reach Me on Nov. 21. McKellen will reprise Gandalf in The Hobbit: The Battle of the Five Armies on Dec. 17.