Derpy is a large, supernatural feline that resembles a tiger. He has cerulean blue fur with black and white stripes across the upper part of his body, and rosette patterns along his chest. His eyes are red with a yellow cornea and often look unfocused, which gives him a permanent derpy expression. He notably sports a perpetual grin on his face that shows off his sharp white teeth. He also has a set of tusk-like teeth that poke out from the top corners of his mouth.