Unlike Gus, Wally's fur is light and tan. He also wears a red rocket suit with a grey belt which has a star on it. He also has green and black eyes and spiky hair, along with a long tail and a pink nose. Unlike his big brother Gus, he has black eyes, which seem blue when enlarged, or in the Monkey Flashback when he was a baby. Wally also has buck teeth and is a little chunkier than Gus. He has a more raggedy tail and bushy eyebrows. Wally also has six toes on his right foot, as revealed in Tail Fail.
Wally is silly and optimistic, goofy, hyper, Darsage's (Darwin-kun) Friend. He likes to be very spontanious when it comes to missions and has more of a "kinder heart" when it comes to people, pets or missions than his older brother, Gus.
Wally has a good relationship with him because YAY-OK helps him with missions and he uses him as a video game player.
He has a crush on her that was shown in the episodes Love on Run and Monkey Hearts.