I don't think you are anything.

[Hal frowns.]

Well you're something, clearly. But you get what I'm saying.

Vampires can only drink human blood. It's an addiction, and as such we're drawn strongly to it. If someone isn't human, or isn't entirely human, it's typically easy to tell upon closer inspection.

I could drain you. I mean, I won't, but I could. The draw just isn't as strong.