In Japanese Buddhism, jikininki ("human-eating ghosts"; pronounced shokujinki in modern Japanese) , also called wendigo are the spirits of greedy, selfish or impious individuals who are cursed after death to seek out and eat human corpses. They do this at night, scavenging for newly dead bodies and food offerings left for the dead. They sometimes also loot the corpses they eat for valuables, which they use to bribe local officials to leave them in peace. Nevertheless, jikininki lament their condition and hate their repugnant cravings for dead human flesh.

Often, jikininki are said to look like decomposing cadavers, perhaps with a few inhuman features such as sharp claws or glowing eyes. They are a horrifying sight, and any mortal who views one finds himself or herself frozen in fear. However, several stories give them the ability to magically disguise themselves as normal human beings and even to lead normal "lives" by day.

Jikininki are preta of the 26th class in Japanese Buddhism. They are also sometimes considered a form of rakshasa or gaki ("hungry ghosts"). In the latter case, they may be freed from their deplorable existence through remembrances and offerings or through the prayers of a holy and/or righteous man that has a truly holy spirit and has done nothing to dishonor his or her family.

http://theunexplainedmysteries.com/Jikininki-Demon.html