kleptomaniac

noun

1. One who steals compulsively.

   ““A kleptomaniac,” I said. “Which means, if the term is not familiar to you, a chap who flits hither and thither pinching everything he can lay his hands on. [...] And if ever a man needed to be constantly under an eye, it's the above kleptomaniac. [...] He pinches things. Everything that isn't nailed down is grist to his mill.””

   “The dear old room was just as I'd left it, nothing changed, and my first move, of course, was to procure another chair and give the top of the armoire the once-over. It was a set-back to find that the cow-creamer wasn't there. I suppose these kleptomaniacs know a thing or two and don't hide the loot in the obvious place.”