Translation: river tengu
Appearance: Kawa tengu are tengu which make their homes along riverbanks and lakesides in eastern Japan. They look like other tengu–vaguely birdlike, with dark feathers. They usually remain invisible to humans, but are sometimes spotted on cloudy or rainy days wearing beautiful kimono and carrying umbrellas.
Behavior: Kawa tengu spend their days alone on the riverside, sitting on the rocks and watching the water as if deep in thought. At night they catch fish. They create magical fireballs called tengubi which float above the water and act like lures. They are fond of creating auditory hallucinations, and are more often heard than seen. The sound of nonexistent rapids or waterfalls coming from valleys is often the work of kawa tengu.
Interactions: Kawa tengu enjoy playing pranks on humans, but rarely do any real harm. They use magic to scare people away if they get too close. If a fisherman casts his net near where a kawa tengu is fishing, it will create illusionary torchlights and the sounds of crowds of people to draw them away. If children play too close to where a kawa tengu is sitting, it will scare them away with illusions–for example, a giant, black monk emerging from the forest chanting, “Children, children!”
If a person purposefully goes looking for a kawa tengu, the pranks can become more direct. Someone leaning over a riverbank looking for a kawa tengu will suddenly lose their footing and stumble head-over-heels into the river. They also create illusory bridges, causing people who try to cross them to tumble and suffer injuries.
Some villagers leave offerings of freshly caught fish by the riverside, or wash the large boulders along the banks. After doing this, the kawa tengu leave them alone.
Legends: Along the Tama River in western Tōkyō, there was a kawa tengu who could be seen every day sitting by a deep pool, lost in contemplation. One spring, however, he mysteriously vanished. In the fall of that year, the kawa tengu returned to his rock, although now he was accompanied by a beautiful young female tengu. A villager offered the pair a nice bowl and tray set as a wedding gift, and the tengu thanked them by teaching them how to make an effective fever medication from worms.
A fisherman was walking along the Tama River, returning home after a day’s work. His pack was filled to the brim with fish. Suddenly he heard a strange sound like a person splashing in the water behind him. He put down his heavy pack to investigate. There was nobody there. After deciding he must have been hearing things, the fisherman shouldered his pack and continued on his way, but it was much lighter than it had been a moment ago. He looked inside, and all of the fish were gone. He had caught so many fish that he angered a kawa tengu, who took them all back.