It was a game that got out of hand. Stumbled on him one night... already cut himself, the big moron. [ How, Spike doesn't know. It was a scrape, enough to fill the air with the scent of blood. ]
We had a rumble, he'd been bragging about how impossible he was to kill... so I ate my fill. Didn't just leave him there after either. Treated him as well as I did anyone who offered.
[ And there had been others. Claire, Garcia that one time... people he took care not to kill. Not even hurt. He could've been alright with that for a while. ]