The Yokai Guyさんのイラストまとめ

Sugawara no Michizane, the god of knowledge, scholarship, the sky, and oh yeah! a terrible onryou as well!

Taira no Masakado: rebel, folk here, and flying severed head which brings disease, disaster, and misfortune to all.

Lady Rokujō from The Tale of Genji.

Shiranui, the unknown coastal flames of Kyushu.

Amanojaku. This is not one of the cute, silly yokai.

Ikuchi, a super-long sea serpent which entangle boats and covers them in slimy oil.

Kawaakago, the river baby.

Hannya, the demoness of classical Japanese theater.

Amanozako, the capricious tengu goddess.

Namahage, the famous demons from Akita prefecture.