Jennifer Lopez first appeared in the Season Seven episode, "Fat Butt and Pancake Head". She is a parody of the real celebrity, and is portrayed as a mean spirited, ill-tempered and egotistical woman who becomes furious when Cartman's hand puppet with the same name steals her fame and boyfriend, Ben Affleck.
After years of success as a recording star, actress and assorted other artistic fields, Jennifer Lopez develops a raging ego and unstable temper, which begins to bother the record executives of her record label. And so when a "younger" and "spicier" performer by the name of Jennifer Lopez appears on the music scene, the executives become anxious to hire her. However, not wanting to have two Jennifer Lopez's signed to their label, they chose to fire the original one. Lopez does not take the dismissal well, blowing up into a furious rage at being told that she was fired and that she was a "mean-spirited bitch, who spits on people for being poor".
She immediately rushes to South Park, with her boyfriend Ben Affleck, so as to confront the new Jennifer Lopez. She's however shocked and confused to find that the new Jennifer Lopez is in fact a ventriloquist puppet of Eric Cartman. Initially thinking it's a joke, she becomes completely enraged when the hand insults her, to which Lopez threatens to kill her and Cartman if they don't back off. Unknown to Lopez however, Affleck immediately becomes attracted to the new Jennifer.
Soon after, the new Jennifer Lopez begins working on her album, and starts dating Affleck behind the old Lopez' back. Again falling into a psychotic fury, Lopez proceeds to attack Cartman's hand with a baseball bat, breaking several fingers in the process. However, the new Jennifer continues to date Affleck and become engaged. This finally sends Lopez over the edge, and she chases down the new Jennifer with a chainsaw, intending to kill her. The police, record executives, Ben Affleck and the boys all chase after the two Lopezes, and Cartman, and are shocked to discover that the new Jennifer Lopez is, in fact, a con-artist named "Mitch Conner". Mitch kills himself with a suicide pill, however Lopez does not return to her music career. Instead she is arrested for assault and attempted murder, and after being released ends up working at a fast-food taco place.
- Assault: In "Fat Butt and Pancake Head", she frequently beat Cartman and Mitch Conner up because she was replaced by Conner posing as Jennifer Lopez.
- Attempted Murder: In "Fat Butt and Pancake Head", she tried to kill Mitch Conner with a chainsaw when she found out he (while posing as Jennifer Lopez herself) and Ben Affleck were getting married.
Jennifer Lopez wears very elegant clothing. She wears a long white skirt, a gray formal shirt with a white collar, a white woman's business coat, and a large white hat with a pearl trimming. She has a plethora of jewelry on consisting of several gold necklaces, a pearl necklace, several gold rings with jewels, a pearl wrist band, and emerald earring. Her accessories include, a white purse with a gold chain handle, white glasses, a pink fur scarf, and a white poodle with an emerald and gold necklace of its own. She has long, wavy brown hair. She also wears make-up consisting of pink lipstick and teal eye shadow.
- In "Proper Condom Use" and "Cartmanland", Stan and Kyle can be seen mutilating a plastic Jennifer Lopez doll.
- "Cartmanland" (mentioned only)
- "Proper Condom Use" (mentioned only)
- "Fat Butt and Pancake Head" - Debut appearance.
- "200" - Jennifer Lopez wants to be part of the angry 200 celebrities.
- "201" - Mitch Conner was in disguise as Jennifer Lopez.