This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Wani (Japanese)
Wani was a dragon or sea monster in Japanese mythology that live in deep bodies of water. They have long, serpentine bodies, fins, and can breathe both air and water. Wani are able to shapeshift into humans, and there are even tales of wani and humans falling in love.
Another mentioning of the Wani can be found in the Izumo Fudoki in the tale ‘Imaro and the Wani.’ Here we see a woman killed by a Wani whilst walking on a beach. Her father enraged asks the kami for help, and going to the beach he sees 100 Wani encircle the one which killed his daughter allowing him to get his revenge.