The unnamed purple doctor is a character who only appears in the episode "Code Yellow."
He is a tall purple fish with a darker fin and lips. He wears a white doctor uniform, with teal pants and brown shoes. His eye color is black and has arched eyebrows.
In "Code Yellow," he and the other doctor are convinced that SpongeBob is a doctor from his white suit. He is initially unsure of SpongeBob's ways of doctoring, but is impressed when his solutions work out. He appoints SpongeBob to operate on Squidward's nose, believing him to be able to do it best. Despite many failed attempts to give Squidward a nose job, the doctors are still impressed that he finally succeeded. SpongeBob tells them he is actually a fry cook and not a real doctor, causing the purple doctor to faint into the other doctor's hands.