Lich is a very rare fantasy mythological creature meaning corpse.
So what makes a lich different from any other member of the undead? Technically speaking a Lich is not a ghost, but rather a physical entity. Though it’s relatively a new comer, it’s very popular. It rose to prominence when Dungeons & Dragons used the Lich as an undead character.
A lich is supposed to be the body of a dead sorcerer who through a ritual called: ,Ritual of Endless Night’ lives on, after his mortal body has perished. More specifically, the wizard can save his soul inside a physical object, which is known as a phylactery. So long as the phylactery remains intact, the Lich cannot be killed.