Monsters: Bekatarō

The  Bekatarō is an ugly, malevolent, and cannibalistic Japanese Yokai. It's believed that it was a wicked child born with a supernatural and unquenchable hunger. They consume anything they can find including humans. It's said that he was so hungrey he started eating humans and thus became a yokai. Their hunger allows them to devour more than what 10 or 20 adults could and want more.  They have a humanoid form and are usually seen pulling their lower eyelids with its finger and sticking its tongues out in a mocking gesture. 

SOURCES:

Yokai

Yokai Wiki

Monsters Wiki