This episode starts out in Skool, with a black box counting down, also with a red button on it. Some kids are scared, some are curious, some are excited... Ms. Bitters presses the red button, and the box explodes, revealing a hamster in a cage. All the kids are excited and rush to see it, and Ms. Bitters explains that it is a program to reduce misery in the classroom, and that they were issued the hamster, named Pipi. Zim is terrified of it for a moment. Zim runs into Dib and tells him that it is a perfectly normal effect on him, and says like the rest of the class, he thinks the hairy monster thing is... and Dib says cute. Zim notices that cuteness has an odd effect on humans, and it makes them weak.
Zim has a visualization of himself riding on a giant Pipi (that's kind of disturbing), and tell the people they cannot resist the hypnotic power of Pipi. The people gather around in awe around the giant Pipi, and he tells them to bow down for Zim. The people start to praise the giant Pipi like it was a God, and it spits fire at the people. The visualization is over, and Ms. Bitters tells the children to take a good look, it will prepare them for their adult lives in the nightmareish corporate system. Zim mutters to himself that it just might work.
Later that night, Zim sneaks into the room... picking up Pipi. The next day in school, A girl is upside down, and Ms. Bitters told her that it has been a minute and twenty six seconds, and that she told them that she said the day before she was going to make their blood rush to their head, and told her she should've trained for it (I really don't understand what that's about). Dib asks Ms. Bitters if she's noticed that the hamster is three times the size and that he has a hideous alien thingy on his back. Zim mutters to himself that it is time to use the Pipi's cuteness to divert attention, and plays with his watch thingy. The hamster goes underground and brings the floor underneath them down as well, and there is a big hole in the wall. Zim tells himself that that was a bit ahead of shedule. Zim crawls out of the hole to watch were Pipi is going, and it has made it to the fence. He took a bite out of the fence and crawled under, getting bigger due to the bite from the fence. Zim screams for his creation to grow, and Pipi is destroying things and eating them, growing larger and larger. Pipi runs through a building, causing mayham. Zim tells Pipi to come and obey him, but Pipi has caused an explosion at a nearby nuclear plant. The news comes on and the anchorman says that there is an Ultra-Pipi causing Mayham in the city, but he says that they all agree that he is fuzzy-wuzzy adorable, but is cut off when Pipi steps on the news building. Pipi takes a bite out of a bus, and uses one of the towers as a toothpick. A woman notices that and stops to see how cute it is, but is crushed as the Pipi throws the bus on her. Zim tells him to obey him, he is his lord and hamster master. People are running and Zim tells them not to fear Pipi, but to fear him. Zim tells Pipi he's doing a good job and to carry on. A man runs screaming for help, and stops and notices his cute feet when he is stepped on.
Meanwhile, military men are discussing how to stop it, and the general tells them he doesn't care how, he just needs it. One of the men tells him that he couldn't fire a missile at that furry face, and Dib barges in saying that he has important information on the Ultra-Pipi, and tells them that the more he eats, the larger he gets. The gerneral tells him good work, and askes how to stop him, but Dib says that he didn't know. The gerneral tells the men to get him, and all the men jump on him. A man tells him that he thinks he knows where he is going.
At Zim's house, GIR is watching The Scary Monkey Show. Zim sits down beside him with those dip stick thingys (the kind that you use a stick to lick and the flavor sugar sticks to it) and askes what he's watching. GIR tells him that it's the scarey monkey show, Zim (as always) says that monkey, and GIR says "it's the monkey." The show is interuppted by a news bullatin, and the reporter says that Ultra-Pipi is headed towards the sewage plant, and if he eats anything, he can grow to unimaginable proportions. There's shaking, and Zim screams about the noise and heads outside. Ultra-pipi has made it to Zim's neighborhood, and yells for pipi to stop, and heads inside to get in his voot-cruiser. Zim starts to fire at pipi, making him angry. He finally swoops down to hit him again, but pipi spits fire at him, making him crash. Dib finds Zim and contemplates on whether to capture Zim or not, but Zim awakes and tells GIR to come and get him. GIR comes to get Zim and they fly off, but Zim comes back and tells Dib that for this once, he agrees that the hamster must be stopped. Zim flys off.
Pipi is walking towards the power plant, and theres a guy there telling them to wait for his mark, but is destracted by his cuteness, which makes his tank get destroyed. Zim trys to tempt Pipi with a giant hot dog from his voot-cruiser, but ends up being chased. The guy comes out of his tank and tells the soldiers to get the weiney. Zim runs off to a faris wheel where there is a giant hot-dog. Pipi starts to eat the wheel, and Zim tells him not to. The soliders get their tanks to where Pipi is, and tells them that they need to use their guns on something, but Dib comes and tells them not to attack, let the alien carry out his plan, and the colonel told his men to put him in a crazy bucket. Zim fires rockets on Pipi, and he is sent out into space.
Zim made it to the ground, and a kid is standing there crying, and asked why. Dib said that alien tampering with earth is dangerous, but Zim shoved him away. Zim tells him, "no matter how cute you create a monster of doom, you have to... I don't know," and told him to stop crying, that he lives on in the starts somewhere, and there is a big crash as Ultra-Pipi hits earth again.
The ending says that no animated characters were harmed in the making of this production.