The Snail Son is a character that appears in Japanese folktales, as a type of enchanted husband that becomes disenchanted from his animal form and becomes a handsome man.
As the tale continues, the mud-snail marries a human maiden, either by trickery or performing honest work to her father.
They leave the rice paddy, and a small mudsnail climbs on the man's knee and begs them to be adopted as their son.
The mudsnail notices his wife's angry mood and asks her to take him to the rock where the old couple pounds straw and, once there, she must crush him.
[4] Seki Keigo collected and published in his book Folktales of Japan a tale titled The Snail Chōja: in the rich lands of a choja (a local wealthy man), lives a childless poor couple.
[6][7] In Hiroko Ikeda's index of Japanese folktales, the character appears in the Japanese tale type 425A, "Mud-snail Son (Tsubu Musuko)",[8] close to type 425 of the international Aarne-Thompson-Uther Index, "The Search for the Lost Husband", and its subtypes of animal bridegroom tales.
[9] In Ikeda's type, an animal son (a mud-snail, a snail, a slug, frog or snake) is born or given to human parents, marries a human maiden and asks her to disenchant him, either by smashing him with a hammer, pestle or stone, or stepping on him; in other tales, she crushes his shell, or he steals a hammer from the ogres and asks her to use it on him.
[10] As cited by Richard Dorson, researcher Tomiko Yokoyama studied the character of the pond snail in Japanese tales, and considered it a messenger from a water deity.
[13] Keigo and Yanagita located variants from across Japan in the following regions: Akita, Aomori, Gumma, Hiroshima, Iwate, Kagawa, Kagoshima, Kochi, Kumamoto, Miyagi, Nagasaki, Niigata, Oita, Okayama, Shimane and Tokushima.
[19] North American missionary Adele M. Fielde collected a Chinese tale titled The Man in a Shell: a woman prays to many gods to have a child.
Insistent and frequent are her prayers that the Sea Dragon King decides to attend her, and the women gives birth to a son with a spiral shell.
One day, the woman asks her daughter-in-law about the snail husband: if he comes out of the shell at night or if he sleeps by the side of the conch.