Jasper is a naturally colored Cheetah with sharp claws and red Jewel Eyes. His fur color is mostly yellow with some brown spots and brown ears with red highlights. He mostly wears a collar with a diamond shaped red Jewel and a tail collar with the same jewel in it. Furthermore, he always seen wielding a huge key, which is used to open portals to other worlds.
In Kira Deco, he is described as a sheriff of Jewel Town and wears a sheriff outfit.
Aside from his regular magic skills, Jasper is the only Jewelpet capable of opening transdimensional gates in all seasons, using his Jewel Key, which is accessed from the gem on his his tail. Because of this, he can easily connect the human world and Jewel Land.