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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BILLY BUSH

Guess no one wanted to be Robin! The Access Hollywood host (right) was 4 when he dressed up as crime-fighting duo Batman & Batman for a New York City Halloween with best friend Mikey Patterson.