>>11527701
And since you mentioned Conan, here's what Skeletor was like as created by Robert E. Howard:

Kull tore the veil away with one motion and recoiled with a gasp. Delcardes screamed and her knees gave way; the councillors pressed backward, faces white and the guard released their grasp and shrank horror-struck away.
The face of the man was a bare white skull, in whose eye sockets flamed livid fire!
“Thulsa Doom!”
“Aye, I guessed as much!” exclaimed Ka-nu.
“Aye, Thulsa Doom, fools!” the voice echoed cavernously and hollowly. “The greatest of all wizards and your eternal foe, Kull of Atlantis. You have won this tilt but, beware, there shall be others.”
(The Cat and the Skull/Delcardes' Cat)