As a Sinner demon, Sir Pentious had a snake-like appearance with a body color predominantly in charcoal grey. His eyes had cerise sclera with black pupils, and a mouth with sharp yellow teeth, two of which were long snake-like fangs. His tail was black with thick yellow stripes featuring numerous cerise eyes running down the length of it. He had a black cobra hood with its front colored yellow with black corners and four cerise eye patterns spread across the center