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: