Just one month after Woody Harrelson came aboard to play the human villain in War for the Planet of the Apes, 20th Century Fox's sequel has added a brand new ape as well. The Wrap reports that Steve Zahn has signed on to play an unidentified ape in the sequel, but it isn't known how his primate character fits into the sequel's story. It's possible that he has some sort of connection with the ape leader, Caesar, portrayed by Andy Serkis, but we don't know for certain.

We also reported in August that Gabriel Chavarria (Lowriders) is being eyed for one of two main human roles in War for the Planet of the Apes, whose character was compared to James Franco's Will Rodman in 2011's Rise of the Planet of the Apes. No plot details have been released yet, but the title is certainly quite revealing, teasing an all-out war between the apes and the humans that was set in motion during last year's blockbuster Dawn of the Planet of the Apes. While there was a 15-year time gap between Rise of the Planet of the Apes and Dawn of the Planet of the Apes, director Matt Reeves confirmed this summer that there won't be a huge time jump with War for the Planet of the Apes.

As for Steve Zahn's character, while it isn't known who he's playing yet, it's possible this character could be taking over as Caesar's second-in-command. In Dawn of the Planet of the Apes, Caesar's right-hand ape Koba (Toby Kebbell) was killed, after he betrayed his leader. It's certainly possible that this new character played by Steve Zahn could be taking over as Caesar's trusted advisor, but we don't know for sure. Last month's report revealed that Woody Harrelson's character is only known as The Colonel, but that's all we know about his character at this point.

Dawn of the Planet of the Apes director Matt Reeves is returning to the helm on War for the Planet of the Apes. The director is working from a script he co-wrote with Mark Bomback, who wrote the script for last year's Dawn of the Planet of the Apes alongside Rick Jaffa and Amanda Silver. Chernin Entertainment's Peter Chernin is producing alongside Dylan Clark, Rick Jaffa and Amanda Silver.

Steve Zahn voices Thunderclap in Pixar's upcoming animated movie The Good Dinosaur, and he will also be seen in Adam Sandler's The Ridiculous Six, which debuts on Netflix December 11. The actor also has roles in upcoming projects such as Captain Fantastic and Robodog, neither of which have official release dates set at this time.