Sssssss released as Ssssnake in the UK is a 1973 horror film starring Strother Martin, Dirk Benedict, and Heather Menzies. It was directed by Bernard L. Kowalski and written by Hal Dresner and Daniel C. Striepeke, the latter of whom also produced the film. The makeup 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 amp Horror Films in 1975.citation needed
Unbeknownst to David or anyone else, Stoner is a delusional man, convinced that humanity is doomed and is attempting to prepare for what he believes to be the inevitable by working out a method of transforming humans into reptiles that can survive pollution and any other ecological disaster that would wipe humanity out.Stoner begins David on a course of injections, purportedly as a safeguard against being bitten by a snake in his lab. Davids skin slowly starts to change and even peel like a snakeskin. David begins a romance with Stoners daughter Kristina Menzies, although her father objects and insists that she not have any sexual relations with him. David becomes increasingly perturbed by the strange side effects of the injections. Kristina visits a carnival freak show and is horrified when she sees a bizarre snakeman, whom she recognises as Stoners previous assistant, Tim. ........
Source: Wikipedia