People are mammals, FWTW. However, I have many doggie friends who think that they are human. They pout, flirt, have tantrums, leap w. joy when humans come into the room, get jealous, are picky about diets, and have hysterics when other dogs arrive.
Good question – I knew a guy who enjoyed pretending to be a dog – an act that was kind of scarry cus he didn’t know when to stop. His facial expression would change such that when I looked at him I would see a dog. His friends called him Joe Animal (at his request)