Archie finds a new weird mystery when Betty reports odd noises in her house in the middle of the night. Initially, he suspects ghosts or poltergeists. However, the effort to track down the answer leads into the sewers under Riverdale, where toxic waste has spilled and something huge and scaly lies waiting...
This episode includes examples of the following tropes:
- Absurdly Spacious Sewer: The sewers of Riverdale are more than big enough for three teens and a mutated alligator. The humans don't even have to bend over to walk around.
- Fluffy the Terrible: Jughead names his pet alligator Peanut. This was already a bizarre name for a creature that would grow up to be an apex predator, but it became even less apropos after she mutates.
- Insistent Terminology: Archie insists that "ghost" is a nasty term; he prefers "dimensionally displaced person."
- Line-of-Sight Name: Jughead names Peanut, his pet alligator, after the packing peanuts she likes to bite.
- Mundanger: Archie's had to deal with aliens, ghouls, a mummy, an evil genie, and more unusual things. This Monster of the Week is an alligator. A giant alligator that walks semi-upright, but just an alligator nonetheless.
- Never Smile at a Crocodile: Played with; the alligator is aggressive at first. However, despite being mutated, Peanut, Jughead's pet alligator, still remembers his owner and he eventually is taken to Florida to be taken care of.
- Pet Baby Wild Animal: Jughead gets a pet alligator, which is small enough to travel in an unobtrusively sized box. Veronica accidentally throws it into the toilet and flushes it, much to Jughead's grief.
- A Pet into the Wild: Played with; Jughead eventually consents to have Peanut taken away by officials. They may not return her to the wild, but she'll at least have an environment more to her liking than a house or sewer.
- Sewer Gator: The Monster of the Week is a sewer gator that grew to enormous size and started walking on two legs after being exposed to toxic waste. Originally, it was Jughead's pet before Veronica flushed it and he gets the gator to stop before it does any more damage.
- Toxic Waste Can Do Anything: It mutates a baby alligator to a large, semi-upright version within a day or so.
- Wait Here: When Archie goes to save Jughead from the alligator, he tells Betty to stay aboveground to direct rescuers, saying that they wouldn't know where to look otherwise. She only listens for a while.
- Younger Than They Look: The mutated Peanut looks like an adult alligator, despite still being a baby.
