An
undead warrior, of the
Animated Skeleton variety, who has the rights and responsibilities of a
Knight in service to its
Lord (usually also an undead.)
I contend that the Skeleton Knight is an
undead archetype - it's not difficult to imagine a
skeleton in battered
armor, with chipped
sword and cracked
shield, mounted on a
skeletal warhorse, discharging some grim
knightly duty to his
infernal Lord. It is considerably less compelling to imagine a
zombie knight,
vampire knight (is the
horse a vampire too? Does it only
prey on other horses?), or
mummy knight.