Who knows, maybe Rockstar will add zombie DLC to GTA Online -- but modders aren't waiting around for it to drop. Instead, they're going ahead and just adding zombies into the game themselves.
While there are a few floating around on the web, this particular zombie outbreak mod comes from Chr0m3xMoDz. It's not the most elaborate, fleshed-out mod -- there's only one zombie model right now -- it's still impressive considering its on a console. Kind of makes the PC release of GTA V all the more unbearable, eh?
And yes, you can play the mod with friends: