Царевна-лягушка
The frog or toad appears as a potential suitor to a female human in variants of the Aarne–Thompson–Uther type ATU 440, "The Frog King". The most famous is the story of "The Frog Prince". It also appears as a female bride in tales of the ATU 402 type, "The Animal Bride", such as "Puddocky" (German fairy tale), "The Frog Princess" (Russian fairy tale) and "The Three Feathers" (German fairy tale).