#398.2

folk literature/fairy tales or classical/romantic german literature (1750 - 1832)

Spriggans are Cornish faery creatures with irregular features & large heads on small bodies. They have nasty dispositions & haunt ruins & barrows where treasure might be. They mislead travelers & can call up storms.

Folklore in general is classified under 398 (with emphasis on 398.2), though you may have more luck finding specific examples in the 800s under each language's specific literature

The fern flower is a mythical flower from Slavic folklore. Whoever finds it gains wealth, luck or the ability to speak to animals. However, it gives access to riches and therefore possible corruption, so whether you choose to pick it or not is a choice. 

The pooka is an Irish fairy creature that usually appears heavily furred and with glowing eyes. However, it is a shapeshifter and can take any form it likes and commonly moves about as a horse. The unwary, and usually drunk, may be taken on a ride on a pooka’s back that leaves them with no memory. During these rides fences and crops are destroyed. In the morning the pooka throws the rider off its back.

The Leshy is a Slavic forest deity that runs with wolves and bears. He watches over the forest and will sometimes lead travelers astray.

The Kikimora is a Slavic household deity. She’s female, lives behind the stove and squeaks like a mouse when she wants food. She is considered the dark spirit to the good domovoy. There are two kinds, the swamp and the forest kikimora.