Opening with a young girl getting a pet baby alligator at an alligator park (after an alligator attacks an employee) whose father decides to flush the gator down the toilet. Playing into the old urban legend about alligators living in the sewers, this film adds an animal testing conspiracy to the mix.
Robert Forster is a Detective named David investigating dog corpses and human body parts popping up at the local waste treatment plant. His defining character trait is being embarrassed by his thinning hair. he brings this up often. The little girl from the beginning grew up to be Marisa, a zoologist who specializes in reptiles. When David discovers that the killer leaving around body parts is a giant alligator, she helps give him insight. It has been feasting on the carcasses of dogs used by a pharmaceutical company in growth hormone experiments.
When people try and catch the alligator, it goes above ground and starts killing people left and right.
Alligator is a rather goofy film. David has a trauma related to a partner who was killed and he blames himself. He does not just get help Marisa, no they start sleeping together. The evil company eventually sees their comeuppance is a bloody finale.
Notably, this film pulls a Jaws, killing a kid. But unlike Jaws, where that is played as a major tragedy that haunts Brody, here it is just one of many scenes with no real impact to the story.
I do like this creature feature overall, even though it does not have a lot of emotional weight.