Okay I am looking for the title of a movie that I believe was either made in the late 70s or the 80s. Its very similar to teenage mutant ninja turtles and night breed. Okay it is about people living in a underground community that appears to be a sewer system. Some of these people look normal but some are downright not. There is a character who appears to be some kind of doctor, he is helping a man with a leg problem and the mans leg temporarily turns into a lizard before becoming a leg again. There is a creature in this movie that is literally a human arm with a snake like tail. Does this sound familiar to anyone.