Japan's founding myth tells the story of a crocodile princess called Toyotamahime, wife of Prince Hoori. She asks her husband not to look at her as she gives birth, but he disobeys her and so sees that his wife is a crocodile. Finding out that she has been seen, the princess goes back to her country, that is, the bottom of the sea. The tale can be compared to the one about Melusine: in both stories there are common motifs such (...) as the command not to look and disobeying the command, as well as the transformation into a reptile. Both stories are also tales about the founding of a royal house. This paper shows how Japanese myths, closely connected to maritime traditions, are at the crossroad of a cultural circulation extending from China and Korea to Indonesia, India, Arabia and Egypt. The chief actors in these stories are monkeys, hares, crocodiles or turtles. (shrink)