Sir Pentious is a slender snake-like demon whose body color is predominantly a charcoal grey. His eyes have cerise sclera with narrow black pupils, and he has a wide mouth with sharp yellow teeth; two of which being long snake-like fangs.

His neck is long and his tail is black with thick yellow stripes featuring numerous cerise eyes running down the length of it. He has a black cobra hood with its front colored yellow with black corners and four cerise eye patterns spread across the center.