I loved this movie! The filmmakers of this 2004 comedy/horror flick said they tried to make a movie that would feel like a 70's drive-in movie, although set in modern times. The succeeded admirably.
Every drive-in cliché is here, and everything about the movie is well-done cheesiness. When a fish farmer's fish start mutating beyond belief (20 eyes, for example) Dr. Barbara Michaels, openly gay biologist from the EPA, comes to town to investigate possible pollution from the town's chemical plant. She doesn't mind, because her girlfriend Trixie happens to be the bartender at the local Moose lodge.
Evil plant owner Huntley Grimes has been hounded by the EPA for 30 years, so he's having chemicals dumped in a landfill near the town's water supply (and the fish farm's lake). When Barbara shows up, he convinces brother-in-law Sheriff Buford Lawson that he's being harassed, so the Sheriff sets up surveillance on Barbara.
When Barbara sends a badly mutated tadpole for analysis, it comes back with mutant genes that are similar to, but not, human. She explains that if one of these tadpoles were to grow into a frog, it would be driven to mate with its genetic match, the closest of which would be a human female. Inevitably, she's called a wacko dyke.
Suddenly a giant man-sized frog shows up and starts raping the local young women. Since poetic justice is an absolute requirement of this genre, his first victim is the plant owner's daughter.
This is just classic drive-in stuff, a ton of fun to watch, and updated with plenty of nudity, lesbianism, etc., but still just as cheesy and funny as the original. A must see!