Dover Publications send me a free sample of their images every week. (You can sign up here.) Because they deal in old books and images, the free samples are, of course, without context. Today they sent me, among others, this image of a whale being flensed, from a book called Medieval Life and People.
See the whale? It has a fish face. It has a fish backbone and tail (bending from side to side rather than flexing up and down). But it has breasts. The person drawing this clearly knew the whale was a mammal and put the most obvious secondary sexual characteristic (of human mammals) on it to prove it. Yet he drew it as a fish, as though he hadn't looked at it closely. Pressure to please his fans, who probably thought whales were fish? Didn't pay attention? Never saw the actual scene but had it described by a whale fisherman who knew what sort of animal he was catching?
What a fascinating drawing.