NINGEN

Origin: Japan(again)

With arms, legs, and five fingered hands, the Ningen's most horrifying feature is its resemblance of Voldemort face(basically human face without nose). In fact Ningen(word) means human in Japanese. But when you see a glimpse of its noseless face, fins and tail, there's no mistaking this creature and Voldemort

Sighting: 

2007,Upon first sighting, members of a Japanese research ship thought they were seeing a foreign submarine off in the distance, upon getting closer, they realize it was a living animal. eventually the creature went back underwater.

Logic: 

Just exist and take credit of being the first stage evolution of human beings.