Amanda "Mandy" Valdez is iCarly's self-proclaimed biggest fan. She is described as an extremely hyperactive and annoying when around Carly, Sam, and Freddie. She first appeared in "iAm Your Biggest Fan". In both of her appearances she tries to guest star on the iCarly webcast.
Mandy's dad apparently left her, so she lives with her mom and aunt.
Mandy likes to do impressions of a duck, and even owns a mask with a duck face on it. At the end of the episode, Mandy had a liking for the band, Backflesh. However, her obsession began on them, and one of the band members asks if someone can call the cops on her.
As Mandy grows up, she turns from being an annoying child to an annoying teenager. Mandy comes back in "iWant My Website Back", where Nevel Papperman tricked her into thinking he was Freddie so he could steal iCarly.com. Carly and Freddie did not know who Amanda Valdez was, until they clicked on her picture, (at that point, they started screaming in horror).
Sam gets her to blow into a plastic bag to keep her quiet in "IWant My Website Back" after she tells the iCarly trio she has a plan, but she needs 3 zebras.
She is quite skilled at decorating cookies to make them look like people.
In the book form of "iAm Your Biggest Fan", it said that she was 12 years old.
She appears in the video game iCarly 2: iJoin The Click.