The Well of the World's End

[1] His source was The Complaynt of Scotland, and he notes the tale's similarity to the German Frog Prince.

[2] Like that tale, it is Aarne-Thompson type 440, "The Frog King" or "Iron Henry".

She gave her a sieve and ordered her to not come back without filling it at the Well of the World's End.

The stepmother was angry at her return, and when the frog arrived, she insisted that the girl keep her promise.

The tale is classified in the international Aarne-Thompson-Uther Index as type ATU 440, "The Frog Prince".