He is usually an overweight dark teal anchovy with yellow eyes and a light teal under side with light teal arms and legs. He also wears a white short sleeved shirt and blue shorts.
He also sometimes appears to be a light green or light indigo with three blue spots on his right cheek and light blue arms, lips, legs, and a dorsal fin. He wears a tan shirt and brown pants in these forms.
He explains that he has "sand in his buns," which are sandwich buns, possibly Krabby Patty buns. He later uses his sandy buns as musical instruments (by rubbing them together) during SpongeBob's song.