Creepy guy on the train

I sat across from a creepy guy on the train the other day. He had longer blond hair (think Lancelot from Shrek) and had this weird, Luna-Lovegood-esque, airy look to him that was sitting on the fence between total innocence and serial killer. He wore stonewashed cargo-jeans from straight out of the early 90's and - get this - I never saw him blink.

When I sat down he just stared at me. It was uncomfortable. (If I make eye contact at all with people on the train it's just a quick nod of acknowledgment and that's it.)

After he was done looking at me he stared out the window. I, too, looked out the window, thankful to be free of his eerie gaze only to see him staring at me in the reflection! At that point I think I peed myself a little.
As I looked down toward my bag (to get my Moleskine to record the experience) I noticed his thumb had a sore on it and it was bleeding. My first instinct was to tell him about it so he wouldn't get blood all over his cargo jeans, but then I stopped myself and watched in horror as he raised it to his mouth, sucked on it a bit with that dreamy/spaced-out look on his face and put it back on the seat next to him. He did this a couple more times, seemingly gaining some unholy power from drinking his own blood.

At one of the stops a girl about our age came and sat next to him. She was frail looking, as if she'd been battling some disease her whole life and would break in half if she tripped.

Our friend the psycho stared at her with unblinking eyes, looking her up and down a couple of times before lifting his hand and sucking on his wound again.

Extremely creepy.

Nothing ever came of it. I haven't seen the guy since, thankfully. But come to think of it, I haven't seen the frail girl either...