You wake with low, guttural groan, feeling weak and tired. What happened? You remember coming into the room, and seeing... You push yourself up suddenly, remembering the undead moose coming up behind you. Twisting around, you see the huge animal on the far end of the room. At least, you think it is the same animal. But this one is healthy, showing no sign of injury at all. And there is no mess in the middle of the room - so why is it sticky around you?
Looking down, you try to scream, only to have the sound gurgle in your throat. Your gut hang out of huge tears in your chest and stomach, ribs broken and jutting through skin, all of it looking gray and rotting. The pooling liquid under you is your own! The moose somehow made you the undead creature! You cry out, making a low moan, and manage to drag yourself up to unsteady legs. Oddly, you don't feel pain. You don't really feel anything. Except hunger. You must have something. Something specific. A brain.
That's when you reach up and feel the back of your head - or where it should be. The top and back of your skull is gone, along with the brain that should have been inside it. The moose ate your brain, and now you are the undead until you eat a brain to replace yours!