Probably the best celebrity prankster is the lovable Ellen DeGeneres. Here's some great ones!

In this prank, Ellen sends soccer star David Beckham undercover at Target. He's forced to say anything Ellen tells him to as he tries to sell his own brand of cologne. People start to catch on that he is in fact David Beckham.

Like with David Beckham, Ellen sends 'Modern Family' star Sofia Vergara into a store to talk to the clerk about a bogus movie, doing what ever Ellen says. She laughs, she cry's and acts like a total nut bag! She's a great spot though and even cracks Ellen up back in the studio.