What is "akaname"

The is a demon or yōkai from Japanese folklore. Akaname means filth licker in Japanese; aka is an homonym for red and filth, so the akaname is often described as being red in colour.

The akaname is the "personification of the fear of using a dark bathroom late at night". It is said to come out at night to lick up the grime and dirt that accumulates in unclean bathrooms.