From Julianne Hough's 'Crazy Eyes' blunder to Matt Lauer's terrifying Pam Anderson, these are some of the worst celebrity Halloween costume offenses ever committed.
Don't worry, kids -- 'Gangnam Style,' the infectious viral hit by Korean rapper Psy, is bound to run out of steam sooner or later, right? Wrong. Last night on the MTV EMAs, host Heidi Klum starred in a brief clip with Psy and broke out her best horsey dance.