Team Fortress 2 is the sequel to the game that put class-based, multiplayer team warfare on the map. It delivers new gametypes, a signature art style powered by Valve's next generation animation technology, persistent player statistics, and more.
This is a hat that replaces the Ellis hat, into a Jack Skeleton Hat. Jack Skeleton is from Tim Burton's: The Nightmare before Christmas. I never saw the movie myself, but i find that the character is quite popular.