Lisa Simpson

From the animated TV show The Simpsons (05/08/05).

In the "A Star is Torn" episode, Lisa (voiced by Yeardley Smith) enters the Krusty the Klown Li'l Starmaker Competition, a preteen American Idol spoof. The first round puts her up against much better singer Clarissa Wellington (voiced by real Idol Fantasia Barrino), who sings the same song Lisa planned to sing ("Mocking Bird"). Dad Homer Simpson saves the day by quickly writing Lisa a pro-Springfield song that panders to the crowd. (Having previous songwriting experience with his barbershop group The Be Sharps.)

Homer becomes her manager, quickly turning into a domineering stage mother as he cranks out schmaltzy, crowd-pleasing songs to make up for Lisa's lack of technical abilities. Lisa finally gets sick of Homer's oppressive managerial style and fires him. Homer then manages her top competitor Cameron instead, renaming him Johnny Rainbow and changing his own name to "Colonel Cool." (Homer had previous experience briefly managing country singer Lurleen Lumpkin.)

In the final round, when Clarissa is eliminated and it's down to just Lisa and Cameron, Cameron loses with a Homer-penned tune about how rich and privileged he is. Homer deliberately sabotaged Cameron so Lisa would win. Awww!