From Japanese Buddhist mythology, Jikininki are the spirits of selfish, greedy, or ungodly people who have passed on. They are said to be cursed to eat the flesh of human corpses. It is also said that they take valuables from the corpses, in order to bribe local law-enforcement officials to leave them alone. Unlike most demons, they actually hate what they are, and are in a constant state of self-disgust and self-loathing. Some accounts state that they are so terrifying to look at, that seeing one would make you paralysed with fear. Other accounts indicate that Jikininki can take the form of normal human beings, and can even lead seemingly normal lives by day. They are notable in that – unlike other gaki or rakshasa (“hungry ghosts”), and ghosts in general – they are an endangered species, if one can use such a term in this context
Kappa are Japanese flesh-eating water imps who live in rivers, lakes, ponds, and other watery realms. They smell like fish and are generally portrayed with the body of a tortoise, ape-like head, scaly limbs, long hair circling the skull, webbed feet and hands, and yellow-green skin. They are often depicted with a tortoise shell attached to their backs. Some say they can change colour like the chameleon. They abhor metal objects and loud noises (cannon fire, gunfire, etc.).
The defining characteristic of the Kappa is the hollow cavity atop its head. This saucer-like depression holds a strength-giving fluid. Should you chance upon the quarrelsome Kappa, please remember to bow deeply. If the courteous Kappa bows in return, it will spill its strength-giving water, making it feeble, and forcing it to return to its water kingdom.
About the size of a child aged 6 to 10, the Kappa is nonetheless incredibly strong. It attacks horses, cattle, and humans, usually dragging its prey into the water, where, according to various legends, it feeds on their blood, or drains their life force, or pulls out their livers through their anuses, or sucks out their entrails, leaving nothing behind except a hollow gourd. In some tales, the Kappa is associated with theft and raping women. Stories tell of Kappa pulling little children into the water and drowning them. In many localities, drowning is still referred to as GAPPADOKO ガーッパドコ (e.g., near Nagasaki in Iwate Prefecture).