Conan's foe Xaltotun. Undead and lichlike.

'You _are_ Xaltotun!' cried Orastes. 'You are not dead! You live!'

Free original story, The Hour of the Dragon, to read here: 

http://www.gutenberg.org/cache/epub/42243/pg42243.txt

And this page talks about the foe, at least where he appears in the comics I take it:

http://www.marvunapp.com/Appendix/xaltot.htm

Real name: Xaltotun

Identity/Class: Human
(Hyborian
Era) magic user

Occupation: Sorcerer, would-be World Conqueror; former
High Priest of Set


Base of Operations: currently unknown; 

formerly Python, Acheron; Khemi, Stygia; Nemedia; HYBORIAN
ERA

First Appearance: REH's "Hour of the Dragon" from Weird
Tales (1935-1936), 

Powers/Abilities: Xaltotun was a sorcerer of great
knowledge and power. In the time of Acheron, he was perhaps the most powerful
mystic on the planet. His powers were vastly amplified when he used the
Heart of
Ahriman, which enabled him to cause sudden floods,
avalanches, deadly plagues, and other forces of mass death and destruction.
He could cast illusions, generate consciousness-robbing mists, paralyze others
on contact, and animate inanimate objects. His own abilities, however, could
be overcome by another learned mystic in possession of the Heart of
Ahriman.

Xaltotun also held other magic items, such as the Heart of Tammuz, the Hand
of Nergal, a Sleep Crystal, and others.

Weaknesses: One of Xaltotun's weaknesses was the Black
Lotus, a narcotic drug which would rob him of his senses when he enjoyed
its effects.


History: Xaltotun was the High Priest of Set in the
city of Python, in ancient Acheron, @ 13, 000 BC. In that role, many blood
sacrifices were performed on the altar of their snake god.