Master Rilla is Jungle Fury Rangers' mentor and bearer of the Gorilla Animal Spirit. He has ability to pound his chest to make a soundwave.
He fell in the great battle against Dai Shi along with the Master Guin and the Master Lope. He now resides in the Spirit Realm. When Dai Shi captured RJ, the Jungle Fury Rangers returned to the Forbidden Room to locate masters to assist them in rescuing RJ. The rangers were greeted by Master Mao. It was discovered that RJ, Masters Phant, Swoop, and Finn were the only living masters on Earth. The other masters were located in the Spirit Realm. Master Mao sent the rangers to the Spirit Realm where they encountered the Gorilla Master and two other masters. After training him, Master Rilla passed his Gorilla animal spirit on to Casey for overcoming his fears.
In Now the Final Fury, Master Mao along with Master Rilla, Master Guin, and Master Lope come through the Spirit World portal to join the Rangers in the Beast War. During the fight, he fought and defeated the Red Shadow Guards. Calling on the full power of their animal spirits, the Masters are able to send the Beast Army back into the Spirit World. However, this victory is also moot when Dai Shi drains the Masters of their Spirits' powers. Fortunately, his powers were returned to him by the Rangers.