Cosplay (コスプレ, kosupure?), short for "costume play", is a type of performance art in which participants don costumes and accessories to represent a specific character or idea.
Cosplay involving the Warcraft universe is very popular and is extremely ubiquitous during BlizzCon.
Rubies.com is an official Blizzard partner company and the largest Halloween and Masquerade products manufacturer and distributor in the world.
1UP.com Blizzcon 2010 Cosplay Gallery
MMOSite.com BlizzCon 07: Cosplay Top 10 Date: 2007-08-06