I haven't heard of thieving Pokemon... I doubt they're quite as interested in worldly things as people are. At any rate, the ones that amicable are few and far between. I've only met one, really.

[As if by telepathy (Anders doesn't know the half of it) the Espurr in question knows it's being talked about and scampers over to shove its face in front of the PokeGear. Its trainer is already feeling a little comforted with the creature in his lap.]

Speak of demons and they shall appear.