Tesso (鉄鼠てっそ, "Iron Rat") was a rat yōkai who framed Kuroro as an evil demon while disguised as human.


Tesso arrived at a village in the guise of a faith healer. There was a nekomata named Kuroro that was adored by the children. Tesso used to villagers to drive her by claiming that the twin tail "invites calamity." Kuroro hid herself in a cave after the attack. This was done to ensure that Kuroro would not become a hindrance to his true plans.

After driving her out, Tesso unleashed a massive horde of demon rats onto the village and had them devour everything in their path so that he might grow more powerful. Inuyasha and the others trace to origin of an ominous aura to a temple that had a barrier around it. Inuyasha breaks through it using the Red Tessaiga. Tesso then destroyed the temple by dramatically increasing his size. Despite his size, however, he still should his fear of cats when Kirara confronted him. He was attacked by Inuyasha's Kaze no Kizu. He appeared to have been destroyed, but he quickly regenerated his body. He mocked Inuyasha for not having enough power to destroy him. Miroku intervened by stating that it wasn't Tesso's true form, and that his sword would not work on him. He attempted to use his Kazaana, but Tesso transformed into fog, and disappeared.

Tesso followed the scent of the village child Koume in an attempt to eat her to increase his power. He was confronted by Kuroro while Koume attempted to escape with Kuroro's kittens. Despite their difference in size, Kuroro was able to hold Tesso. He then used an energy blast from his mouth that caused a cave in where Koume was. Luckily Shippō was with her, and was able to help escape the cave. Tesso was waiting outside for Koume. He attacked Shippō in order to reach Koume. It was than that Shippō noticed that the wounds on his body that were inflicted by Kuroro suddenly disappeared. Inuyasha suddenly intervened after bing guided by Kuroro. Realizing that Tesso current form was a fake, Miroku a sacred sutra to detect Tesso's whereabout. The sutra landed on a rock where Tesso had hidden his true form. He was killed by Inuyasha with the Kaze no Kizu. The plague of rats ended with Tesso's death, and Kuroro was welcomed back into the village with her kittens.

Powers & Abilities

  • Transformation (変化, へんげ, "Henge"): Tesso can take the form he wants, since at first he is seen as a human before revealing his rat form. He also disguises himself as a rock before he is killed in an attempt to save himself.
  • Barrier: Tesso can create a barrier with evil energy that he uses to protect his temple while he has his rats attack the village.
  • Malignant Fog: Tesso emanates evil fog while performing his spell. It can be transformed into a cloud of evil energy.
  • Energy Blasts: Tesso is able to shoot beams of energy from his mouth.
  • Illusion: Tesso can create illusions. He creates a colossal version of himself, which can be regenerated if it is attacked.