He is a small kitten, being shorter than even Benny, with white fur and a tan muzzle. He has bright blue eyes with black pupils and little ovular eyebrows that are dark in color. On the top of his head he has a tuft of fur that curls more than the rest of his fur, and the fur on the sides of his face are styled in a way that makes his head look almost diamond-shaped. He wears a small brown hat at the top of his head, and a green plaid top with two brown buttons. The shirt's collar are a similarly brown color, and he wears a red bowtie. His tail is short and triangular, much like a real kitten's tail.
Sheldon is sweet and naive, and completely trusts and adores his uncle. Not only was he very impressed with Top Cat and NYC, and completely fell for Top Cat's millionaire ruse. He is also quite childish - being a kitten - and likes to play in the water with other children. He has an interesting way of speaking, saying "gosh","golly", and "jeepers" quite frequently.