Cartman excitedly brags to the other boys that he is the first to reach puberty, since he's gotten his first pubes. However, it turns out that he bought them from Scott Tenorman for $10.00. Cartman tries to get back his money through various methods, but is always outwitted by Scott, losing an additional $6.12 in the process. Ultimately, Scott lights his money on fire and Cartman start screaming in rage and promises revenge. First, he tries to get his friends on his side, but because Cartman is the only victim, none are interested. Cartman's first major plan involves training one of Farmer Carl Denkins' ponies to bite Scott's penis off. He trains one to attack a scarecrow with a hot dog hanging from its pants. The pony doesn't bite it off the first time, instead giving it a blowjob. Jimbo and Ned turn up, stating that the best way to humiliate Scott is to exploit his weaknesses. When they stake out the Tenorman house that night, Cartman discovers that Scott is a fan of Radiohead, and begins developing a scheme. However, Jimbo and Ned are distracted by the fact that Mrs. Tenorman is showing her breasts. They, along with several other men, are caught by Mr. Tenorman and run away.
Cartman's plan involves dubbing his voiceover that of the Radiohead members to make it appear that the band is telling Kurt Loder that Scott Tenorman is "totally not cool". This plan fails, and Scott further humiliates Cartman by showing the entire town a video of Cartman pretending to be a pig to get his money back. Cartman abruptly becomes a laughing stock in front of the whole town (Kenny even dies from laughing too much at the video). Cartman then proceeds to carry out a variation of his plan to get Scott's wiener bitten off. He invites Radiohead to come to South Park to meet Scott (who is, according to the letter, dying from cancer in his butt) and asks if they are free "next Tuesday around 5". Stan and Kyle betray Cartman, warning Scott that Cartman is out to get him. Cartman invites Scott to a chili cook-off, telling him that he can have a free pony ride at the event. Scott, who thinks he knows what Cartman's plan is, tells his parents that there's an abandoned pony at Farmer Denkins' place. His parents then go to Farmer Denkins in order to have the pony sent to an animal shelter. Scott decides to humiliate Cartman once again by having all the kids in South Park put their pubic hair in Scott's chili and watch Cartman eat it.
At the cook-off, everybody is waiting for Cartman to get humiliated (except for Chef, who brought his own chili). Scott eats Cartman's chili first, and then taunts Cartman to do the same. When Cartman has eaten most of a bowl of Scott's chili, Scott begins to tell Cartman what he did. However, Cartman has anticipated Scott's move, and reveals that he switched Scott's chili with Chef's. He explains that he knew that Stan and Kyle were going to tell Scott about his original plan. He also explains that he knew that, as Scott wouldn't want his wiener bitten off, he would send someone to get the pony for him, most likely his parents. What Scott didn't know is that Farmer Denkins is a crazy redneck who shoots trespassers on sight. Knowing this, Cartman warned Denkins that violent pony killers were in the area, as Denkins wouldn't want his favorite pony killed. Upon seeing Mr. Tenorman's flashlight, Denkins shot Scott's parents, killing them. Cartman stole the bodies and spent the night chopping them up with a hacksaw and cooking them into his "Mr. and Mrs. Tenorman Chili", which Cartman reveals he has just fed to Scott. After that is revealed, Scott pulls out his mother's finger out of the chili with a diamond ring on it. Scott (and everyone else present) is horrified and devastated at the loss of his parents (and that Scott had also committed cannibalism). Cartman then jumps up on the table and mockingly sings, "Nyah nyah nyah nyah nyah nyah! I made you eat your parents! Nyah nyah nyah nyah nyah nyah!". At that moment, right on cue (and exactly on Cartman's schedule), Radiohead shows up. They see Scott sobbing and mock him for being a "crybaby" and "totally not cool" and they leave Scott sobbing.
Finally, as Scott is crying over the death of his parents, Cartman victoriously licks the tears off of Scott's face, remarking that they are "yummy and sweet", as well as calling them "The Tears of Unfathomable Sadness." Kyle remarks to Stan, "Dude, I don't think we should ever piss off Cartman again.", to which Stan agrees, both horrified at the depths to which Cartman went for revenge.
"Scott Tenorman Must Die" is among the most popular episodes of South Park, and is one of the most notorious episodes, according to Stone. "Scott Tenorman Must Die" is often regarded as the greatest episode of South Park ever made, and has frequently topped many "Best of" lists for South Park episodes including lists by WhatCulture, IGN, and Kotaku. Parker and Stone chose the episode as one of their eleven favorites in 2003, and one of their ten favorites in 2006. Fans voted the episode into the 2nd place in a major 2011 South Park voting held under the "Year of the Fan" promotion. The first place was taken by the tenth season episode "Make Love, Not Warcraft".
The events of this episode are given new meaning in the season fourteen episode "201", in which Scott returns as the leader of the Ginger Separatist Movement, revealing to Cartman that, while researching his revenge upon Cartman, Scott learned that his own father Jack Tenorman (a fictional Denver Broncos right tackle) had fathered Cartman with Cartman's mother Liane. This means that Cartman is responsible for his own father's death and feeds him to his half-brother in "Scott Tenorman Must Die".
In the 2009 video game South Park Let's Go Tower Defense Play!, the player has to fight Scott Tenorman in a boss fight. In the 2012 game South Park: Tenorman's Revenge, the player is able to control the four main characters of the show, who have to battle Tenorman and his army of gingers, as the kids travel through time.