Golden Ring
In Greek tale, "The Merchant's Daughter", Daphne, the youngest of the titular merchant's daughters, asks for her father to bring her "The Golden Ring". The Golden Ring is a prince from a foreign country who, after meeting the merchant, tells him he saw Daphne in his dreams and wishes to marry her - an event akin to variants of Scandinavian tale "The Green Knight". He metamorphoses into a pigeon to meet Daphne by her window.