Oni

Lock the door, blow out the light;
The hungry Oni haunts the night.
Hide and tremble, little one;
The Oni wants to have some fun.

Hear it scratching on the door;
See its shadow cross the floor.
The sun won't rise for quite a while;
Till then, beware the Oni's smile.
-Children's rhyme

Summary

Parents tell unruly children that they must behave and go to bed at a decent hour, else an Oni will find them in the night and eat them. Many parents who cannot control their children use fear as a last resort to keep them in line. While most parents know that an Oni is a real creature, they don't believe an actual Oni attack is possible. Little do they know...

Historical Basis

Oni are real creatures that do, in fact, eat children. Though real, they are exceedingly rare and hunt in rural locations to avoid contact with adventurers. This just makes it more convincing for young rural children to listen to their parents to not be susceptible to the Oni. Unfortunately, the children don't know that if an Oni truly wanted them, they would carve right through their parents.

Spread

The legend is known around the world and is transcends races and social classes, however it is far more popular in rural areas, as they are the target demographic. Despite an Oni sighting in Callisto in 25,252, very few children who live in the city fear the Oni's tale.

In Literature

Oni are a common antagonist or monster in children's books. They are portrayed as a corporeal boogeyman that can be killed, which makes for a thrilling story of adventure where children are the protagonists.