Perverse

His pranks are sinister and macabre, but each one offers a critical life lesson to his hapless victims. His neighbors, coworkers, and acquaintances rarely associate their strange misfortunes with the odd young man in their midst. Yet he is always watching, always aware, and his cunning mind is inevitably filled with delightfully perverse plans for their future.

Any outcome is possible given proper context, impeccable timing, and the right props.