|Manga||Yōkai Castle (1966)|
|Anime||Episode 3 (1968)|
|1968 anime||Kōsei Tomita|
|1985 anime||Hiroshi Ōtake|
Masashi Hironaka (Ep. 74)
Kōji Totani (Kusa-Kamaitachi)
|1996 anime||Takuma Suzuki|
|2007 anime||Masami Kikuchi|
|2018 anime||Taiki Matsuno|
|Other anime||Hiroshi Ōtake (2003 PS)|
Despite his name, the Kamaitachi from Yōkai Castle does not resemble the weasel yōkai of legend. However, there is also a more accurate Kamaitachi called Kusa-Kamaitachi (草かまいたち, Grass sickle weasel), who appears in Saishinban GeGeGe no Kitarō.
Shigeru Mizuki's design of Kamaitachi is different from the weasel yōkai of legend. He is a short man with a short haircut and an elongated mouth, similar to an anteater's snout. He usually wears a robe, though in the 5th anime he wears a kimono and haori.
In the sixth anime, Kamaitachi has light purple skin, with pointy ears, short orange hair and several scratch marks across his face. He wears a dark brown, full body robe, that reaches to his feet and hands. After being resurrected by Nanashi, a dark inverted pentagram appears on his forehead.
The Kusa-Kamaitachi has the more familiar weasel form. He has sickles for forearms, green fur and yellow eyes.
Yōkai Castle Kamaitachi
Shonen Magazine/First Anime
Kamaitachi works with Tantanbō and Futakuchi-Onna at Yōkai Castle, kidnapping children to convert them into yōkai. He was defeated along with Tantanbō when Kitarō forced Nezumi-Otoko to place a rope seal around the castle, turning it and everyone inside into stone. He appears in the third episode of the 1st anime adaption, Yōkai Castle.
In Yōkai Mannendake he reappears as an ally. He chops down several yōkai bamboo with his sickle arms, but when confronting Mannendake's true body his sickles break. Afterwards he takes part in the final battle against Mannendake.
He appears in the first episode of the third anime adaption, The Mysterious Yōkai Castle Appears!!. In this adaption, the Yōkai Castle story went the same way as in the manga, but Kamaitachi safely escapes after being defeated by Ittan-Momen. In addition to reappearing in episode #74 Yōkai Mannendake episode, he also takes part in the battle against Chi (Movie 3), but is subdued and transformed into a Yōkai Cloth. In this anime he has green skin, orange hair and wears a brown robe.
He appears in both episode #66 and #67 of the fourth anime adaption, Ominous Clouds! Yōkai Castle (Part 1) and Ominous Clouds! Yōkai Castle (Part 2). This adaption introduces his sickle arm ability to the anime franchise. This time, his skin is yellow, his hair is brown and his robe is white.
In the fifth anime, he first appears in episode #39 of the fifth anime adaption, Nurarihyon's Last Day, as a freelance assassin hired by Nurarihyon. He is a fan of shojo manga, and Nezumi-Otoko bribed him into helping with Nurarihyon's jailbreak by offering him a shojo manga called "Otome-zaka Korori". When he learns Nezumi-Otoko made the book up, Kamaitachi tries to kill him but is thwarted and defeated by Kitarō. Angry at Kitarō for wounding his pride, he decides to join Nurarihyon's faction to eventually get revenge. His sickle arms are focused on more in this adaptation and he is depicted as being powerful enough to regularly fight evenly with Kitarō. He even once took down 6 Tengu Police at once. In addition to wearing a kimono and haori instead of his regular robe, his blonde hair is slicked back instead of in a crew cut and his skin is pink.
He makes his story appearance in episode #61, Tantanbō of the Yōkai Castle.
He appears in the third episode of the sixth anime adaption, Tantanbō's Yōkai Castle. In this episode, he awakens along with Tantanbō and Futakuchi-Onna. After the trio saw that humans have polluted, twisted, and wounded the world as they pleased, they believed the world did not need humans. They kidnapped 13 children, one of which was Mana, to resurrect the Yōkai Castle and create a world only of Yōkai. He was defeated when Konaki-Jijii in his stone form was catapulted into him by Sunakake-Babaa and Ittan-Momen.
Some months later, Kamaitachi and the others were revived by Nanashi, forming an Obake School where children could come and become ghosts. During one night, he teaches a class middle school students about math through jars filled with blood and liver, asking Sōma to answer a problem and supports him when he could not answer, encouraging him to the do better. The next night Kamaitachi and the others gather the students outside, planning on using them as yōkai fodder. When some attempt to leave, he and Tantanbō stop them. He targets Hiroto sadistically gleeful about wanting to cut his mouth up to his ears, almost poking his eye out and wanting him to scream before Neko-Musume arrives and gets his attention. He joins in the battle against her and Kitarō, eventually being defeated by Neko-Musume.
The Kusa-Kamaitachi appears in the Saishinban story The Seven Yōkai Wonders as one of the titular Wonders. He much closer to the Kamaitachi of legend. In addition to having sickle arms, he can also blow leaves around, using them as shuriken. In the manga he is subdued after being set on fire and flees after revealing where Nurarihyon is holding Medama-Oyaji prisoner.
In the third anime adaptation of the story, he is instead vanquished when Kitarō catches him with the Yōkai Ocarina's whip and slams him into a tree. He blows up without revealing Medama-Oyaji's location.
Kamaitachi has the ability to fly around and high speed, often creating whirlwinds that can cut flesh. Starting with the 4th anime, he also has the ability to transform his arms into sickles, making him closer to the Kamaitachi of legend.
The Kamaitachi is most common in the Kōshinetsu region. There are several conceptions of how it looked or operated, but the most common is one of a trio of weasels with sharp claws, riding on a gust of wind and cutting people's skin on the legs. According to this interpretation, the first weasel knocked the unsuspecting victim down, the second cut the victim's flesh and the third applied medication to the wounds, so that at the time the victim realized what was happening they were left only with painful wounds that weren't bleeding. Sometimes the three are described as brothers, sometimes as triplets. This account can be traced back to Toriyama Sekien, who was presumably also the first to imagine the apparition to have the form of a weasel.
The idea of lightning fast weasels wielding razor-sharp claws appealed to manga and anime artists and the kamaitachi often appear in those media.