As a mummy, it was put in public exhibition held once every 77 years, with a fictional legend that he was about to drag a beautiful shrine maiden he fell in love with into the swamp, but the lady avoided her fate by proposing to become his bride if he wins a sumo match and having him get defeated by a grand champion, and he died from his injuries.
So many exhibitions made him become a Tsukumogami, convinced that it’s a real Kappa and under the impression that its story heard numerous times was a true story.
The day before its latest public exhibition, Ayame took it from its shelf at a shrine to be moved to the main shrine. It had seen a picture of Tsubasa on Ayame's cell phone when she thought about him, and as it was placed right under a roof leak, it came to life by absorbing water, and escaped set on getting revenge on Tsubasa, as he is the latest shrine maiden’s love interest and it abhors the one who supposedly killed it for the fictional shrine maiden. Tsubasa could easily defeat it as it was small, but it would gradually grow bigger by being exposed to the rain. Eventually, it gets its revenge by swallowing an entire swimming pool of water and slamming his huge body against the poor exorcist, who survives nevertheless. As it got satisfied, it turned back into a mummy.
- The Kanji (河) stands for “river” and the Kanji (童) stands for child, but together they mean "Water Demon".