That could also be like that episode of Tales from the Crypt with Don Rickles and Bobcat Goldthwait about the ventriloquist.

It's been too long since I've seen the show, I barely remember that one. I need to go through it again.

Znep, are you knowledgeable about old comics? I have been trying to identify one for years. I just remember it was an old comic that was at a place we went to for a summer vacation once when I was a kid. It belonged to whoever owned the place, or maybe whoever stayed there before us... anyway, the comic was probably from one of the series you mentioned, I think, and one of the stories in it was of a guy who was slowly turning into an alligator or crocodile. He kept going to a scientist who claimed to be curing him, but it turned out the scientist was actually the reason he was turning into a reptile at all. By the time the poor guy figured out what was going on, it was too late, and he turned totally into an alligator or crocodile.

I think he probably ate the scientist before escaping into the local swamp... not 100% sure about that, but it seems like a reasonable guess.

Two things I definitely remember are a drawing of the guy when he was about 80 or 90% turned, running on all fours on a treadmill in the scientist's lab, and an earlier scene where he shed the skin off his hand on a doorknob when he turned the doorknob... it looked like a gray glove coming off his hand, but he was molting a dead layer of skin. He might have had scales coming out under the skin that came off... not sure about that.

Anyway, does this sound familiar to you????

I'm really not knowledgable on the subject at all. That doesn't sound familiar to me, but I do plan to read all of these and I'll let you know if I come across that one.