Every year movie and comic book fans, toy collectors, gamers and more descend upon Comic Con in San Diego, Calif., wearing all sorts of crazy costumes as they roam the halls of the San Diego Convention Center.

Cosplay, as it's known (which is short for costume play), is one of the biggest reasons to check out the annual convention.

Even celebrities get in on playing dress-up -- like former America's Next Top Model winner Adrianne Curry, whose often too-racy costumes were actually toned down a bit this year.

The season one winner attended the convention over its four day run in costume as Batman villains Poison Ivy and Catwoman, along with a day in costume as Watchmen's Silk Spectre.

Stephen Colbert showed up to host "The Hobbit" panel dressed as a Lake Town denizen from Peter Jackson's trilogy.

Jackson himself was able to walk the Convention Center floor incognito as an evil jester, while Mythbuster Adam Savage got in on the action in an amazing replica of the spacesuit from Ridley Scott's "Alien" - complete with a facehugger alien (video below!)

Jack Black wore everyday clothes with a Stormtrooper helmet, while Daniel Radcliffe and Game of Thrones star Maisie Williams wore Spider-Man outfits.