If so, what animal was it and what was so anomalous about it?

I have seen multiple snakes and turtles with two heads. I've seen cats with extra toes, too.

-- BK

sometimes

Once, as far as I remember.

Several years ago, In the cove I tend to visit, there are two species of blenny fishes that live arround one specific rock.

One is tompot blenny, a rather friendly and hard-to-see fish that tends to live in groups. Then there is a red black-faced blenny, the timid species tha trather move in the bottom.

One day, I saw a literal "crossbreed" blenny(?) that had red body and brown head. It was the only one there. I tought it was Tripetrygon Melanarium but no, the fish I saw had red body and branching horns.

When I heard the word "mutant", I was expecting we would be talking about actual mutants, like two-headed snakes, or cats with tentacles and more than two eyes, or even the character Dogpool. These are just hybrids, or animals with rare genes or deformities, hardly what would count as a mutant in the traditional sense. Even calling albino animals, or animals with extra toes such as the cats with polydactylism "mutants" can be considered derogatory since it's the gene that's mutated rather than the animal itself.