Liches do not have much as far as mythology goes, actually, but I shall try and put as much factual data concerning liches down as possible, ignoring all of the undead wizard stuff that D&D built up.
The word "lich" is related to a Slavic word for evil and a German word for corpse. In Catholocism, a lych gate is a covered entrance to a cemetery where a casket is brought before burial (thus the gate in the story). There is also apparently a European goatsucker called the lich fowl (or owl).
Other uses of the word "lich" include the lich wall (which surrounds burial grounds), lich wake (normally just called a wake), lich path (that which leads to a grave and the corpse is carried), and also as a misspelling of the word "like" by old English authors. Reply