Lord Charles Pain is a sycophantic demon who lives in the Plain of Eternal Suffering and first appeared in the episode "House of Pain" of The Grim Adventures of Billy & Mandy.
He was voiced by the late Henry Gibson and seems to be based on Judge Death from 2000 AD.
He traveled to Endsville where he served The Grim Reaper faithfully, until Mandy tricked him into becoming HER servant instead. He later appeared in "Everything Breaks" as Mandy's servant. He renamed the Plain of Eternal Suffering "Level 9" because, according to him, "it sounded more tourist-friendly". He and Billy destroyed everything in Level 9, and then laid waste to Endsville. He later reappeared in a flashback sequence in "Wrath of the Spider Queen". He has pale green skin, carrys a mace and shield, and wears a spiked helmet (which obscures his eyes), a red and black cape with the collar folded up and turquoise armor. He has tattoos all over his body (the first of which he ever got was a dolphin on his left ankle) which originally featured Grim, but later altered and removed to show his devotion to Mandy.
Grim Adventures of Billy & Mandy