The self-mummification procedure takes three years, three months and three days. During this time the holy man fasts and undergoes rigorous exercise to completely purge his body of fat. During the final 333 days of the process he begins to consume small doses of poison, usually arsenic. Finally, 33 days before the end, with the help of other members of his order he shuts himself away in a brick compartment just large enough to allow him to sit in the lotus position. He then waits to starve. Once the 33 days have passed his brothers remove his body from the compartment and position it in a place of veneration. The arsenic in his bloodstream preserves the body from beetles and maggots; his brothers also use various spices and incantations to stave off decay.
After three dozen years have passed, the holy man's soul returns from wherever it dwelt in the intervening period, and inhabits the mummified body it left behind. Sometimes the soul is benevolent and continues to live harmoniously with its brotherly order. Sometimes, due perhaps to the ordeal of the three-year procedure, or because of what happened after, the soul is crazed and incoherent, and requires constant care from its brothers. At others, however, the soul has become twisted and malevolent, with a hatred for all living things. These last often bring with them dark knowledge from the afterlife, and use it to cause pain, sorrow and mischief.
Sokushinbutsu usually wear the vestments of their order, and appear withered and skeletal. They are nearly always eyeless, but nevertheless percieve reality perfectly.
Lawful sokushinbutsu are meditative and serene. They do not generally communicate and spend much of their time in silent contemplation, though sometimes they can be persuaded to perform healing spells or remove curses. They are only ever found at monasteries or shrines in the company of other members of their order, who care for them meticulously. Neutral sokushinbutsu are insane and either catatonic or imbecilic, though occasionally insights about their god, or the afterlife, can be gleaned from their ramblings. Chaotic sokushinbutsu are malevolent and cruel; they usually kill the other members of their order or flee their company, and can most often be found lurking in ruins, caves or graveyards. They are sometimes accompanied by ghouls, who they exercise a strange power over, or, rarely, weak-willed evil humans who venerate them.
Sokushinbutsu[Note: Sokushinbutsu are a genuine phenomenon, and it is believed that hundreds of Japanese monks, mostly in Yamagata prefecture, attempted self-mummification. Only around 20 are thought to currently be in existence. I was going to post a picture of one in this entry, but it felt oddly disrespectful and I changed my mind. Using the concept as inspiration for a D&D monster is one thing, but I thought it would be in rather bad taste to put up a photo of a specific individual. You can find pictures of them on google image search if you're so inclined.]
Armour Class: 6
Hit Dice: 6+4
Attacks: 2 fists
No. Appearing: 1
Save As: C10
Treasure Type: Nil
Alignment: Lawful, Neutral or Chaotic
Sokushinbutsu may cast spells as a level 8 cleric. They can only be harmed by magical or silver weapons.