Tootie is the love interest of Timmy Turner from The Fairly Oddparents.
She is the younger sister of Vicky, Timmy's cruel babysitter and arch-enemy. During the series, she has a massive crush on Timmy, which only terrifies him and makes him want to escape.
It wasn't until A Fairly Odd Movie: Grow Up Timmy Turner where Timmy finally falls in love with her and even grew up, though he keeps his fairies because of his heroic acts in Fairy World. Timmy and Tootie then travel around the world to use Cosmo and Wanda to help other people.