Thunder is an obese purple rhino with a large nose and buck teeth. On his belly is a 6-like bellybutton, as well as wrinkles across his cheeks and eyes and a small tail. His eyebrows are black like all other characters, and the inside of his ears are greyish-purple.
Thunder is a very shy gentle giant, and is also cute, sweet, and cheerful. His favorite thing is singing. He frequently tends to be slower than the other characters, but is easily scared of some things that live in dark places.