Two celebs dressed up as U.S. Olympic swimmer Ryan Lochte this weekend at Halloween bashes... Nina Dobrev and Taylor Lautner! The "Vampire Diaries" star wore her costume to Katy Perry's party at the Hollywood Legion Saturday night, while Lautner, of "Twilight" fame, headed to Matthew Morrison's 7th annual Halloween party presented by Freixenet Cava. Lautner painted his hair white, while Dobrev donned a short wig.