Shirime [尻目]

This odd being was only reported once... but what a report!

Essentially, sometime previous to 1757, a lone samurai (a Japanese swordsman) was walking one night in the city of Kyoto, Japan, when an average-looking sort of guy stepped in his way, and politely stated he wanted to show the samurai something. The man dropped his kimono (robe) and stood naked in front of the startled samurai; and then the man turned around and bent over and... Peek-a-boo! A giant glowing eyeball was staring at the samurai from where the man's anus should have been!

The samurai is said to have fled in fright from the strange apparition and its glowing rectal eyeball.

This report appeared in a scroll made by the famous Japanese poet and artist, Yosa Buson. In the scroll, titled “Buzon’s Yokai Picture Scroll” (蕪村妖怪絵巻) ['yokai' = basically, 'monster'], Buson called this odd monster a 'Nopperabo,' which is another monster in japan that starts off looking human, but then melts or has facial features disappear; and so Buson also drew this monster as having no face, though I can't be sure if that's what the samurai originally reported or not.

In any case while no more reports are known of this weirdo, the sheer silliness of its trick has insured its continued existence in new stories and art. Nowadays, however, the creature sports the more descriptive name of "Shiri-me" [尻目 - Shi-ri-Mei], which is literally Japanese for "Butt-Eye!" It also now tends to be shown with a basketball sized eye on an unrealistic backside, rather than having an anatomically correct butt with an eye peeking out... so more of a parent-approved butt joke now, I suppose.

Personally, I suspect the whole thing was just a particularly successful trick by a Kitsune or Tanuki... oh? Haven't I told you about those yet? Another time, another time.