When Cartman is required to give a report on the effect of Latino culture on the arts in America. He says he has a special guest, Jennifer Lopez. However, Jennifer Lopez does not show up, Cartman merely does a ventriloquist act with his hand acting as the head of "Ms. Lopez". The racism of Cartman's report is quite obvious and upfront. His "Ms. Lopez" hand puppet has a heavily caricatured Mexican accent and constantly talks about eating tacos and burritos which are Mexican dishes despite the fact that Jennifer Lopez is Puerto Rican. "Ms. Lopez" is also completely incapable of pronouncing the "J" in her name (which Cartman tries to correct unsuccessfully). Despite this, the board of Hispanics give him first place for having the best report, and he wins a $20 gift certificate at the mall.
While at the mall, Cartman's hand demands to make a music video at a music store, which gets the attention of Hollywood Record executives. They proceed to hire "Jennifer" because she's supposedly younger and more attractive then the real Jennifer Lopez, who is furious at being replaced. When the Hand-Lopez then steals her then-boyfriend Ben Affleck, the real Lopez goes insane and attempts to murder both the hand and Cartman.
Caught between the psychotic Jennifer Lopez, Ben Affleck, the record executives and the police, "Jennifer" reveals herself to be a male con-artist named Mitch Conner. Mitch confesses to playing everyone for chumps, before "killing himself" by taking a cyanide pill (in truth, Cartman just opened his hand). Cartman explains that the whole thing with his hand taking on a personality was real, stating "Look, I don't care what you guys believe. But with all the crazy stuff that goes on in this town, isn't it possible, just possible, that something I don't understand happened here?" When the others concede that maybe there that it could be believable, Cartman reveals it all to be an elaborate prank he did to screw with Kyle, Stan, and Kenny.
However, "Mitch/Jennifer Lopez" returns in "200". When the celebrities that South Park has wronged over the years plan to take revenge against South Park by filing a class-action lawsuit, Cartman appears amongst them with his hand again dressed up like Jennifer Lopez. Despite having Cartman with "her" the other celebrities immediately welcome her into the group and reveal their plans.
Apparently their plan was to join in on the lawsuit to get money, but Cartman's hand instead wants to help the celebrities steal Muhammad's power of not being ridiculed and sell on the black market. When Cartman refuses to go along with it, Mitch tempts him with the truth of who Cartman's REAL father is. Cartman initially doesn't believe Mitch, stating that his mother Liane Cartman is his father. Mitch explains that the story fed to him was a lie, and that the tests were faked. They then go to Mr. Garrison so as to meet with Mr. Hat, Garrison's old puppet teaching assistant who was disregarded shortly after Mr. Garrison came out as gay. Claiming to be old war buddies, Mitch and Cartman force Garrison and Mr. Hat to admit that the tests were tampered with, and prepare to reveal the truth.
At the end of "201", Cartman's father is revealed to also be the father of Cartman's arch-foe Scott Tenorman, and a former team member of the Denver Broncos, Jack Tenorman. As everyone is recovering from the events of the two-parter, Mitch says goodbye to Cartman, explaining that there is a bounty on him and that he can't stay in one place for long. Before leaving however, he consoles Cartman who is horrified, not by the fact that he caused the death of his own father during the events of "Scott Tenorman Must Die", but instead by the fact that his own father is a ginger. Mitch however reminds Cartman that although he might be part ginger, he was also part Bronco, which cheers up Cartman considerably. Cartman opens his hand once again and Mitch disappears.