People.com's Halloween Party

Before They Were Stars: Halloween Costumes!

See Carrie Underwood as a bunny, Nick Jonas as the Blue's Clues pooch and more stars when they were still trick-or-treating!

15 of 20

JESSICA HARP

The country singer, then 3, looked big top-ready as a clown. "I wanted to be something girly, like a princess, but my mom took her first stab at sewing and made my costume herself," she says.
Boo! Hollywood's Real Ghost Hunters!

Boo! Hollywood's Real Ghost Hunters!

Is Leighton a fraidy-cat? Does Anna believe in ghosts? Find out who jumps at things that go bump in the night!

See Photos