Actor Steve Zahn (Diary of a Wimpy Kid) has joined the cast of War for the Planet of the Apes. He will play one of the titular primates in the film.War for the Planet of the Apes cast includes Andy Serkis, who will reprise the role of Caesar, Gabriel Chavarria (“East Los High”) and Woody Harrelson (“True Detective,” Zombieland).“I know that part of the desire for Matt [Reeves] to do this next movie is about continuing the enjoyment of seeing these apes evolve.