If we had to pick an antagonist for Warm Bodies, it would be a toss-up between the Boneys (see "The Dead" for more info) or Julie's dad, General Grigio. In fact, the General is pretty much a boney, just with more skin. We've got a few pieces of evidence that this dude is as cold as ice:
Exhibit A: His dead wife pretty much killed herself by running away into zombie-infested territory. The General describes her as "so weak" (2.3.8). He could be hiding his sorrow behind a mask of anger, but what's more likely is that she ran away just to get away from him.
Exhibit B: When posed with serious questions about the meaning of life, and how to make existence purposeful, the General shuts down the questioning saying "this conversation is inappropriate" (2.5.27). Why, man? Because it might require you to have feelings?
Exhibit C: R overhears someone saying it "wouldn't surprise [him] if [General Grigio] arranged the collapse himself" (2.6.89). That's a drunk's opinion, and we don't necessarily believe it, but the fact that people actually suspect that the General might have caused the zombie outbreak is proof that he isn't exactly warm and cuddly.
Oh, and we forgot that he tries to shoot his own daughter for macking on a zombie. Yeah. Case closed. It's no surprise that, when eaten by a Boney, General Grigio instantly becomes a skeleton himself. Bye bye, skin. Say hello to your new afterlife. It's not much different than the soulless, heartless, cold life you led.