Russian variants include the Frog Princess or Tsarevna Frog (Царевна Лягушка, Tsarevna Lyagushka) and also Vasilisa the Wise (Василиса Премудрая, Vasilisa Premudraya); Alexander Afanasyev collected variants in his Narodnye russkie skazki. Andrew Lang included an Italian variant titled The Frog in The Violet Fairy Book. Italo Calvino included another Italian variant from Piedmont, The Prince Who Married a Frog, in Italian Folktales, where he noted that the tale was common throughout Europe. Georgios A. Megas included a Greek variant, The Enchanted Lake, in Folktales of Greece.
It is classified as type 402, the Animal Bride, in the Aarne-Thompson index.
The king (or an old peasant woman, in Lang's version) wants his three sons to marry. To accomplish this, he creates a test to help them find brides. The king tells each prince to shoot an arrow. According to the King's rules, each prince will find his bride where the arrow lands. The youngest son's arrow is picked up by a frog. The king assigns his three prospective daughters-in-law various tasks, such as spinning cloth and baking bread. In every task, the frog far outperforms the two other lazy brides-to-be. In some versions, the frog uses magic to accomplish the tasks, and though the other brides attempt to emulate the frog, they cannot perform the magic. Still, the young prince is ashamed of his frog bride until she is magically transformed into a human princess.
In Calvino's version, the princes use slings rather than bows and arrows. In the Greek version, the princes set out to find their brides one by one; the older two are already married by the time the youngest prince starts his quest. Another variation involves the sons chopping down trees and heading in the direction pointed by them in order to find their brides.
In the Russian versions of the story, Prince Ivan and his two older brothers shoot arrows in different directions to find brides. The other brothers' arrows land in the houses of the daughters of an aristocratic and wealthy merchant. Ivan's arrow lands in the mouth of a frog in a swamp, who turns into a princess at night. The Frog Princess, named Vasilisa the Wise, is a beautiful, intelligent, friendly, skilled girl who was forced to spend 3 years in a frog's skin for disobeying Koschei. Her final test may be to dance at the king's banquet. The Frog Princess sheds her skin, and the prince then burns it, to her dismay. Had the prince been patient, the Frog Princess would have been freed but instead he loses her. He then sets out to find her again and meets with Baba Yaga, whom he impresses with his spirit, asking why she has not offered him hospitality. She tells him that Koschei is holding his bride captive and explains how to find the magic needle needed to rescue his bride. In another version, the prince's bride flies into Baba Yaga's hut as a bird. The prince catches her, she turns into a lizard, and he cannot hold on. Baba Yaga rebukes him and sends him to her sister, where he fails again. However, when he is sent to the third sister, he catches her and no transformations can break her free again.
In some versions of the story, the Frog Princess' transformation is a reward for her good nature. In one version, she is transformed by witches for their amusement. In yet another version, she is revealed to have been an enchanted princess all along.