Umimiko (Patreon)

Umibōzu (海坊主, "sea priest") is a paranormal phenomena or yōkai from Japanese folklore.
Little is known of the origin of umibōzu but it is a sea-spirit and as such has multiple sightings throughout Japan. Normally, umibōzu appears to sailors on calm seas which quickly turn tumultuous. It either breaks the ship on emergence or demands a bucket or barrel from the sailors and proceeds to drown them. The only safe way to escape an umibōzu is to give it a bottomless barrel and sail away while it is confused. 

Trademark folklore:

Umimiko is a lonely gal who likes to swim alongside other creatures, but she's clueless about why people fear her.  If she sees a ship sinking (Or accidently sinks it herself) then there goes giant fat lifesaver honkers to the rescue. 

Umi means sea while Miko means priestess or shrine maiden.