A Kawahime is a type of monster in Japanese folklore that was believed to haunt water (especially near bridges and watermills).
Appearing as beautiful women they would seduce men and then feed on their life-force.
While almost exclusively beautiful women some accounts also gave Kawahime kappa-like appearances, this could be due to Kawahime shapeshifting or mistaken identity (as kappa, like many yokai, can also change shape).