Jax is an anthropomorphic cartoon rabbit. He has long bunny ears on the top of his oval-shaped head, and his overall build is tall and slender, with a rather long neck. Jax's eyes have yellow sclera, with square black pupils. He’s laid-back, calm, sassy and impulsive.

While the other Evil Big Tops are incorrigible and mean, Evil Jax, ironically, is shown to be friendly and shy, the opposite of Jax himself. He has pink fur and purple overalls, the opposite of Jax’s clothing and appearance.

