Urpgor

Urpgor is in somewhat rare company in the history of children's TV cartoons, as he's one of the few characters I can think of (Zordrak is another) to be depicted actually deliberately killing another character on screen. In S02E01 "The Nightmare Stone", he uses the nightmare stone to murder an urpney guard with nice shoes (said smoking footwear is all that remains of him afterwards).

Did the likes of Skeletor and Mumm-Ra ever actually kill anyone on screen? I remember most cartoons of that era being very careful to show that nobody ever died (e.g. the Decepticons would shoot down some jets, and they made sure to show all the pilots bailing out).