Humanoids from the Deep (1980) from Johnny Web (Uncle Scoopy; Greg Wroblewski)

That sounds like a cue for a flashback.

Sinister forces turn out to be responsible for the disappearance of the salmon from local waters. The owners of the cannery company had been doing some DNA experiments on salmon and they accidentally released genetically altered salmon into the ocean. The altered salmon were eaten by predator fish, and that diet turned the predator fish into - you guessed it - Humanoids From The Deep. (Add echo chamber in your mind). For some reason there are no female humanoids from the deep, and these aquatic monsters have super-evolved brains and understand the need to propagate their species. Serendipitously, they are capable of impregnating human females. (Hey, that's why they are called "humanoid." In all fairness, they do appear to be approximately as human as Vic Morrow.) Unfortunately for the lonely monsters, human males do not surrender their mates easily, so the humanoids need to kill human males in order to mate with human females.

First they come upon a girl and her boyfriend camping on the beach. He is a ventriloquist. They maul the voice-throwing twerp, but the dummy's eyes continue to follow the action even after the ventriloquist is dead! This apparently supernatural phenomenon is never explained. (Hey, it's a Corman movie). The monsters proceed to rape the girl. Later, another girl's boyfriend is feeling her up in the water, and the humanoids watch from an underwater vantage point which makes them really horny, so they kill yet another twerp, and rape yet another girl. Later, in the movie's final scene, we see that very girl giving birth, and ...  well, I think you can probably figure it out.

Meanwhile, the elders of the town meet to plan their next move. Let's see, they know that the monsters are dangerous to humanity, and they also know that the monsters' preferred diet is salmon, so what should do they do next? What else? They decide to go ahead with the 93rd annual Salmon Festival! Actually, it wasn't an easy choice. The resolution to "hold the salmon festival" won by a 5-4 vote over a competing bill to "put up a neon sign welcoming salmon-eating monsters."

Oh, we humans are a foolish lot, at least when we take the form of movie characters.

The movie's climax comes at the Salmon Festival itself, a carnival where humans and humanoids alike meet to share a few memories. The humanoids show that, while they are not smarter than average humans, they are quite a bit smarter than carny folk, and smell a lot better as well.

Dental care is about even.

Before tracking down the prized Salmon Queen, the monsters stop to ride some of the midway rides (I didn't make that up. Hey, they are genetically advanced). Of course, while they enjoy the carousel, they take the extra time and trouble to slaughter the human males on the ride.

Then one monster stops for some cotton candy, for beneath his scales he is a man, and not by salmon alone does man live.

The easily-distracted humanoids then head over to the midway to play some carny games. One of them gets really hacked off that he can't knock down the bowling pins and win an Eeyore to woo the Salmon Queen, especially since he has seen some other humanoids with Eeyores and even one with a Tigger! Then he really gets steamed when he realizes that those other monsters were audience plants who were allowed to win by the carny barkers in order to sucker in more players. Of course, when Mr. Humanoid discovers this, he rips the carny geek limb from limb and resumes chasing the Salmon Queen, intending to take her by force if he cannot woo her with presents. At one point a humanoid rips off the bra of the Salmon Queen while chasing her through the midway.

But, by jingo, we humans are not defenseless, you know. Our salmon queens can take care of themselves, thank you very much. This gal squares off and dukes it out with the big guy.

The human spirit endures.

So if you evil super-intelligent movie humanoids are out there reading this review, listen up, buccos. You'll never take us. If you think you can just come here and rape our women, Mr. Johnny Monster, you've got another think coming. We've got mighty tough Salmon Queens and Bruce Willis, and no movie monster or asteroid is any match for our spunky little race.