Alligator (1980) 

Lewis Teague directed this sly horror-comedy from a script by John Sayles, which plays off the old urban legend about the dangers of flushing one's pet alligator down the toilet. One such unlucky reptile is "Ramon," who survives in the subterranean cesspool by feeding on the steroid-saturated carcasses of dogs dumped there by chemical company researchers and eventually bulks up to the size of a Winnebago. When assorted sewage workers start disappearing into Ramon's massive maw, hard-boiled cop David Madison (Robert Forster), who has a history of unlucky partners, reveals a strong personal interest in the case. Deemed a jinx and a nutcase by his superiors, he's kicked off the force and must go underground (literally) to destroy the beast with the help of young reptile-expert Marion (Robin Riker). 

- AMG

Rating: 3.5/5 Scars

External Links:

 

Watch Full Film

Source 2