Blood?

I'd been tracking the man, knowing I'd wounded him, an ever-growing feeling that something about him wasn't right sitting in the pit of my stomach. No man I knew ran after taking a blade though the shoulder. I'd excused it to adrenalin, or that I was mistaken as to the depth of the cut. Something, anything, to push back that uneasy feeling that this man wasn't normal. Wasn't human.

But now, as I squatted; staring, not daring to touch; I couldn't hid the fact any longer.

The black sludge; still warm, still dripping from the leaves; was definately his version of blood. And the heat, if I could judge it using human standard's; indicated he, it was close.