Uminaoshi

Description
The Uminaoshi are a mass of glowing tendrils which feed on the time a person has been alive. They then send the person back to an embryonic stage so they can be reborn.

They are found in underwater trenches, and don't come out when the moon is visible. When it is a full moon, they release the embryonic eggs back to the water surface. If one swallows these eggs then the child in the embryo can be reborn.