Debut -- Killed By Death (Season 2)
Died Same Episode
Der Kinderstod is first seen by Buffy when she's in her fever-induced kind of state at the hospital. She later learns from Ryan that what this thing is is Death. It's good she found this out, otherwise she might have agreed to play chess with him.
Anyhoo, this monsterrific thing is dressed all in black, has wacky longish gray hair, kind of like one of my old anthropology profs, except hers was in a braid and was a bit longer, and has a new-Fang-led mouth that would give Angel and Spike a run for their money. Or something. This cat's quiet, for death. I mean I guess if you believe that death sneaks up quietly and all, then this is your guy.
He's also obsessed with his hat. Like, when he sees Buffy peering at him, he takes off his hat, as a gentleman of old might do, and then puts it back on again. And later during his fight with Buffy, he picks up his hat and dusts it off. Whatever. I guess every monster has to have some kind of quirk, you know?
The interesting thing about this death guy is that he can't be seen by adults...according to the book that Cordy found on him, he feeds off of children by sucking the life out of them. It's kind of what his name means, Child Death. After he's done, it appears as though the kids died because they were sick. Giles elaborates further by saying that Dr. Death sits atop his victims, rendering them helpless. After Buffy hears this, she realizes what happened to her cousin Celia.
Anyhoo, Buffy kills DK by snapping his neck as he's about to suck the life out of her. To see how he sucks the life, check out the last picture on this page. It's freaksome. It's all in the eyes.
Der Kinderstod's Victims of Late: