Krusty met Sophie's mother while he was performing with a USO tour during the Gulf War. They had a romantic night of passion, but in the morning Erin realized she had to complete her mission -- to assassinate Saddam Hussein. Krusty told her not to go, insisting that she had a new mission, to "get down with the clown". However, she left anyway and Krusty ended up tackling her just as she was about to kill Saddam with a rocket launcher, protesting that she couldn't kill Saddam because he was half of Krusty's act. Now angry with Krusty for ruining her mission, Erin began hating Krusty. She also came to hate clowns in general, and filled her house with artwork depicting violence against clowns.
Erin never told Krusty about her pregnancy and raised Sophie as a single mother, only telling her daughter that her father was "some pathetic clown", and Sophie researched that on the internet and found Krusty.
Sophie first met Krusty during an autograph session, where she revealed to him that she was his daughter. Krusty said he wanted to reunite with Sophie's mother, but she angrily rejected him. Sophie loves to play the violin and she played for Krusty. He loved her performance, but later lost her violin to Fat Tony in a poker game, and recruited Homer to help him get it back.Their relationship is eventually mended when Krusty and Homer steal the violin back along with money inside the violin case.
Sophie also likes to play soccer and was seen playing in a match where Homer was the referee.
Comic Book Series
In the Simpsons Comic #95, Sophie stops by the Simpson house to see her father, who is staying there as Marge's life coach. After meeting him again, she mentions that her mother is on a top secret military mission to assassinate an evil dictator. During her stay, Lisa chooses to befriend her, since they both play musical instruments, but Bart objects to this and says that he will befriend her, thinking that it will help him become Krusty's number-one fan. After annoying her enough, Sophie proclaims that she is unable to take anymore pressure and she and her father storm out, concluding that Bart and Lisa are nuttier than bridge mix. Krusty finds her comment hilarious and plan to get together the following weekends to make fun of the Simpsons some more.
- Sophie and her father both share the same hair color and religion.
- Despite having a Jewish father, Sophie was raised Christian by her mother, as revealed in "The Nightmare After Krustmas".
- She is one of two characters to appear in only two episodes, with the first being mainly about them. The other is Mr. Bergstrom.
Note: The episodes in bold indicate major roles.
- Episode – "Insane Clown Poppy"
- Episode – "Marge Gamer"
- Episode – "Judge Me Tender" (Mentioned)
- Episode – "Pranks and Greens" (Mentioned)
- Episode – "The Nightmare After Krustmas"
- Episode – "E My Sports"
- Episode – "Marge the Lumberjill"
- Comic book – Coach Me If You Can Comic book – Coach Me If You Can
- Video game – Tapped Out