An update to iPhone's Plants vs. Zombies hit today that adds the ability to play as zombies in the game, a new free level and some festive hats for the holiday season.

The game's I, Zombie mode, which is already available on the PC, Mac, XBLA and DS versions, allows you play as the zombies in the game. The update also adds eight additional levels, and an endless mode that you can purchase in the game's in-app Crazy Dave shop.

Other additions includes GameCenter leader board support and four new achievements.