As if slaying your way across a zombie-infested wasteland as a pack of gun-toting raptors wasn't awesome enough, modder Lurch of the L4DMaps community offers the Stay Puft mod which replaces Left 4 Dead 2's burly Tank with the soft and tasty juggernaut from Ghostbusters.
It's a pretty basic mod—a simple reskin of the Tank is all you'll get for less than a megabyte's download. Some default animations don't exactly translate well in those rolls of sugary goodness, as the model's arms stick out awkwardly and ragdoll effects are anything but smooth. Rock tosses are subsequently hilarious-looking. (You'll see what I mean in the short video I recorded above.) Still, making the conscious decision to shoot at and be chased by a grunting behemoth of marshmallow should count for something.