Grateful dead (or grateful ghost) is a folktale present in many cultures throughout the world. The most common story involves a traveler who encounters a corpse of someone who never received a proper burial, typically stemming from an unpaid debt. The traveler then either pays off the dead person's debt or pays for burial. The traveler is later rewarded or has their life saved by a person or animal who is actually the soul of the dead person; the grateful dead is a form of the donor.
The "grateful dead" story is Aarne–Thompson–Uther type 505.
An ancient Egyptian text explains the principle of reciprocity in which the deceased calls for a blessing on the person who remembers his name and helps him into a happy afterlife:
But if there be a man, any one whomsoever, who beholdeth this writing and causeth my soul and my name to become established among those who are blessed, let it be done for him likewise after his final arriving (at the end of life's voyage) in recompense for what was done by him for me, Osiris.
One variant is the Book of Tobit. The chivalric romance Amadas has the title knight pay his last coins for such a burial. It appears in various fairy tales, such as the Italian Fair Brow, the Swedish The Bird 'Grip' and H. C. Andersen's The Traveling Companion.