The Kappa (河童?) are a race of amphibious Kappayokai from Japanese legend that made appearances in the 1968 Daiei film, Yokai Monsters: Spook Warfare, the 1974 Toho series, Go! Ushiwaka Koujirou, the 2006 Kadokawa film, Great Yokai War, and the 2010 Nikkatsu film, Death Kappa.
In both of its appearances, the Kappa's appearance is identical to typical depictions of its kind in media. The Kappa is a small, reptilian creature with a pool of water on its head, and 'leaves' running around the rim of its pool. The Kappa also has a beak, which gives it a vaguely avian appearance as well.
While the Kappa himself didn't appear in the first of the Yokai saga films, there is mention of the mischievous water imps.
In this film, the Kappa has one of the most important roles of the whole film, and is one of the protagonists. He was the first yokai to challenge Daimon, getting his head dish severely burned while doing so. The Kappa then went to the other youkai for help, and though suspicious at first, he rallied the troops. He was thought to be killed in the large assault on Daimon when his head dish caught fire, diving into a pond. Daimon how ever, set fire to the pond. It was later revealed he was perfectly fine and 'waited out the storm'. Besides him, there were many Kappa that were in the spirit army that fought against Daimon and his illusions, using their power of water to drench Daimon's flames.
Much like 100 Monsters, the Kappa isn't seen, but is mentioned. It is possible there are Kappa in the massive crowd scenes of Yokai spying on two bandits.
A Kappa appears in Go! Ushiwaka Koujirou as an enemy monster and ally of Konjo.
Much like he did in the Showa series, the Kappa played a major part in the Great Yokai war of 2006. He was one of the first yokai to respond to the call when the youkai found out that their species were being turned into mindless machines. Unlike the Showa Kappa, this Kappa had no powers besides reverting back to his normal size when being crushed by a boulder.
In this film, the Kappa is looked after by a woman, but the Kappa is wanted by a band of criminals and mutant fish men. They threaten to use a bomb to destroy all of Japan, and eventually do set it off. However, one of the fish men is caught in the explosion and is mutated into the monster Hangyolas. Fortunately, the Kappa was also mutated into Death Kappa and was able to subdue the rampaging titan. After its fight with Hangyolas, it was soothed by its childhood friend who sang it a song and poured water on its dish. The Kappa, losing its red eyes, slowly disappeared into the ocean.
- Kappa can headbutt his opponents.
- Kappa is able to shoot a water beam.
- When mutated, the Kappa can breath blue atomic breath similar to that of Godzilla.
- When mutated the Kappa can use a variety of physical attacks, e.g. flipping Hangolas, much like the legend of Kappas being professional sumo wrestlers.
- The Kappa from Spook Warfare could see the inner spirits of people, and was able to identify Daimon hidden inside a person he possessed.
- The Kappa from Spook warfare frequently teleported while trying to assault Daimon.
- The Kappa from Spook Warfare and the one from Great Yokai War are implied to be the same Kappa.
- The Kappa in Great Yokai War apparently knows of the Yokai based series, Gegege no Kitaro and berates people for not enjoying it.
- The Kappa, much like Gamera can be seen as a protector of children. It wasn't until Daimon began to feed on the blood of children did he try to rally the other Yokai, and forty years later, he became friends with a boy who could see Yokai naturally.