After mentioning this at the opening last March of Broadway's Of Mice and Men, Parrack confirmed he wasn't kidding when he reiterated his taste for blood in a recent interview with Vulture.
"I was being literal. I like the real deal," the actor said, but that doesn't necessarily mean he's quenching his thirst every day.
"Maybe a couple times a year? It's more like on an impulse," he said. "When you make me spell it out like this, it sounds strange, but I just want to be clear – that night, I was being literal. There was something about that night where I had that impulse. I guess the best way to put it is, sometimes I just like the way it tastes."
While he may drink human blood, the actor, who recently split from his wife of six years and is now engaged to Hunger Games actress Leven Rambin, is choosy about whose Type A he will throw back.
"I'm absolutely particular," he says. "It's not like it's just anybody's! That particular night, it was my girl. Yeah."
And the reason behind his blood-drinking habit? It's simple.
"I guess for the same reason some people want alcohol? Or, for the same reason some people want, I don't know … milk? Or Kool-Aid," he says.
Still, Parrack keeps it in small doses.
As he insists, "I don't mean copious amounts of blood. I'm not getting a glass of it or something. But if you drink it, it does something to you emotionally. It's hard to describe. It's like you're in the moment, and the impulse comes, and … I like it."