Jax appears to be a lilac cartoon rabbit whose design evokes the look of early cartoon characters, also known as "rubber hose" characters. 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. Jax's yellow teeth usually have a flat shape to them, but when his mouth is opened, his teeth appear sharp and jagged. (or if taken context of that scene, it also can be a one-time thing purely made for comedic purposes.) Jax has thin eyebrows that appear in the majority of the scenes.

Jax wears light pink-colored overalls and pale yellow gloves. His overalls have yellow buttons on them and also have a single lighter pink rectangular pocket on the front and lighter pink sections on the bottom hem of his overalls.