鬼
おに · oni · JLPT N3 · noun
monster
👹 Oni likely comes from on (隠), hidden: the unseen being that lurks
A traditional etymology links oni to 隠 (on, hidden), so the first oni were unseen spirits. In tag, the chaser is called the oni. Hook: oni, ON the hunt for you.
鬼 — head 田 + legs 儿 + 厶
鬼 is a pictograph of a figure with a large, eerie head (田-shape) atop human legs (儿), with 厶 suggesting a swirling or sinister element. It originally depicted a masked spirit or the soul of the dead. The meaning broadened to 'ghost, demon,' and figuratively 'sneaky' or 'clever.'