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!

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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.