I remembered this made for TV Movie called SSSSSssssss. It was about a guy who slowly turns into a snake. The visuals of the character in between the metamorphosis scared the hell out of me as a kid. I was terrified by it.
Thanks Andy! All film fans (especially HALLOWEEN fans) should run over to THE HOLLYWOOD SALOON A.S.A.P. and wet their whistles on their incredible podcasts! Check'em out HERE