Iris is a new student at Harding Middle School. When she meets Ricky Beamer, the two become fast friends. However, Iris quickly becomes witness to Ricky's constant torment at the hands of other kids. Among Ricky's many bullies is Tasha McClain, head of the school paper. In an effort to get revenge on Tasha, Ricky prints a message in the school paper asking "creeps" to give her a call, providing her phone number. The plan backfires almost immediately for Ricky. Iris calls to tell him that his own phone number was printed, rather than Tasha's.
Things only get worse for Ricky, as eerie voices begin calling him in the middle of the night. The voices tell Ricky they are creeps and want to know when they can meet. Ricky soon meets the beings behind the calls -- a group of shape-shifting lizard creatures known as Creeps. They tell Ricky they want to turn the whole school into creeps via seeds. Scared, Ricky bides his time as the creeps attempt to plant the seeds. He tells Iris of his problem, and she tries her best to help.
Eventually, the creeps get Ricky to insert the seeds into the cookies being passed out at the school bake sale. Ricky plans to tell the students of the creep's plan, but the kids begin chanting mean nicknames, and he decides to follow through with the plan. The book ends with Ricky himself becoming a creep. Whether Iris becomes one or not is left unrevealed.
Iris is Ricky's only true friend. She is kind, and helps him deal with the constant pressure of the creeps. She is shown to be quick-witted when she pretends to be a creep general. However, despite her friendship with Ricky, she is unable to prevent him from turning himself and the whole school into creeps.
In the book, Ricky describes Iris as cute, with a round face, blue eyes, and blonde hair. In the TV episode, she is Filipino and has dark hair.