There is a kind of fish called a sheepshead that comes in varieties so diverse that one wonders why they are considered a single kind of fish. For example, one sort gives you psychedelic hallucinations. A non-hallucinogenic kind has almost-human teeth:
But here is the Asian sheepshead, and you cannot make this stuff up.
That is one ugly fish, unlikely to show up on your menu. Like its human-toothed conspecific, it does not give you hallucinations. It is an hallucination. Sheesh.
Undoubtedly, someone can come up with a Darwinian adaptationist just-so story that neatly accounts for this fish's head. My theory is: a) mutations happen, b) this mutation neither killed the fish nor impeded reproduction, and so c) here it is. Since the fish uses its head in some manner or other, one can point to this usage and claim that this was the telos for which it was naturally selected; but it is surely just as plausible that the telos was the fish's drive-to-survive.
Why it's called a sheepshead is a mystery.