Sven- Sssssss

From wiki-  Sssssss^[i] is a 1973 American body horror film directed by Bernard L. Kowalski and starring Strother Martin, Dirk Benedict, and Heather Menzies.^[4] Its plot follows a college student who becomes a laboratory assistant to a herpetologist who is covertly developing a serum that can transform human beings into snakes.

The make-up effects were created by John Chambers and Nick Marcellino. It received a nomination for the Best Science Fiction Film award of the Academy of Science Fiction, Fantasy and Horror Films in 1975.  Back to me:

Alas, this is not a good movie.  Great makeup effects, but rather boring the rest of the way.  I first saw it on network television after Battlestar Galactica began its short prime time run.  I am quite sure I have seen it in the last few years on Sven, but was less impressed as a grown up than I was as a teenager being bored by the movie.

Next- War of the Gargantuas!