That’s a good episode, what I remember is that Cartman shows Kyle, Stan, and Tweek an advertisement he found for “Sea People” (a parody of Sea-Monkeys). Cartman (led along by images from the ad) imagines them to be a race of fish-form people similar to mermaids who will “take me away from this crappy goddamn planet full of hippies.” He convinces everyone, including a very skeptical Kyle, to chip in so they can buy them.
Meanwhile, Butters, in his evil alter-ego persona Professor Chaos, is still trying to figure out a way to bring disarray to the town. When he plots to block out the sun, his assistant, Dougie/General Disarray, informs him that it mirrors a plot of Mr. Burns’ from The Simpsons. Frustrated, Butters abandons the idea.
That night, Cartman dreams (and sings) about going to live among the Sea People, but wakes to learn that the “sea people” are just brine shrimp, typically used to feed fish. Desperate to derive amusement from their purchase, the boys decide to put them in Ms. Choksondik’s coffee. She then dies (as had been announced in the previous episode two months before).
Butters then instead decides to cut the head off of the town’s central statue — which mirrors Bart Simpson’s decapitation of Springfield’s Jebediah Springfield statue. On the news report, the newscaster interprets Butters’ vandalism as a homage to The Simpsons and even reports that the police are not going to investigate the crime because they want the statue to remain headless as a tribute to The Simpsons.
Upon hearing on TV that semen had been discovered in the teacher’s stomach, the boys come to the conclusion that they inadvertently killed Ms. Choksondik with their “sea men”. That night, they go to the morgue to steal the sea men evidence, fearful that they’ll “find the women too!” Meanwhile, Butters continues to devise other, increasingly outlandish, evil schemes, but Dougie keeps pointing out that every one of Butters’ plans have also already been done on The Simpsons.
Eventually, Chef explains to them that there is a difference between “sea men/semen” and “Sea People”, and that the brine shrimp couldn’t have killed their teacher. By this time, the semen they recovered had been added to the Sea People remaining in Cartman’s aquarium. To his extreme surprise, when Cartman wakes up the next morning he discovers that the semen have caused the Sea People to rapidly evolve into a thriving society of about Sumerian or Babylonian technological advancement, which leads him to propose his own Theory of Composite Dynamics: “Sea-People + Sea-men = Sea-Ciety.”
In an attempt to come up with an original evil plot, Butters watches every single episode (he states that he has watched all 132 episodes of the Simpsons, twice, though 291 episodes of the Simpsons had actually aired before the original air date of this episode) before introducing his newest evil plan: build a machine that replaces the cherry centers of chocolate covered cherries with rancid mayonnaise (a plot that Dougie/General Disarray dismisses as being too unoriginal to appear on The Simpsons). Right as Butters is about to put his device into use, a Simpsons commercial announces that Bart is going to do the exact same thing in that night’s episode. Butters has a nervous breakdown and begins to picture the town in the animation style of The Simpsons.
Back at the Cartman household, the boys have bought more Sea People, a larger aquarium, and several gallons of semen. (Cartman says, “Yeah, I bought all that I could at this bank, and then I got the rest of it from this guy named Ralph in an alley. And the sweet thing is, the stupid asshole didn’t even charge me money for it, he just made me close my eyes and suck it out of a hose.” [this was edited out in some airings]) Their Sea-Ciety continues to evolve, into an Ancient Greek-esque civilization, and they begin to worship Cartman as a god, even building a statue. Much to Cartman’s delight, accepting his divine kingship gladly by shouting, ‘I am god of the Sea People! I am master of their great sunken empire!’
Stan and Kyle invite Butters, along with others, to come see the aquarium. Hysterical, Butters realizes that the Sea-Ciety plot is very similar to that of the “Treehouse of Horror VII” short “The Genesis Tub”, wherein Lisa Simpson brings to life a civilization in a tooth. The boys agree with him, but they don’t see much problem with this, noting that in its long run The Simpsons has done everything, so worrying about that is pointless. Chef then points out that they in turn borrowed their ideas from a classic Twilight Zone episode, The Little People. Butters understands and everyone quickly returns to their normal appearance. At that point, Butters happily leaves, getting ready to wreak havoc once again, in which everyone proudly compliment him to do so. Meanwhile the Sea People on the other side of the aquarium begin to worship Tweek, leading to a holy war, complete with suicide bombings (a parody of the Arab-Israeli war). Only seconds later they develop nuclear weapons and completely destroy themselves and the tank.
