The good old folk tale about Vasilisa the Beautiful and Ivan Tsarevich. Ivan Tsarevich, by the will of the father-tsar, married a frog. Ivan was already grieving, but there was nothing to do. Once the tsar invited his sons and daughters-in-law to a feast. When the Frog Princess arrived there in the guise of a beautiful girl, Ivan Tsarevich, not teasing himself with happiness, burned the frog skin of his wife, which forced her to return to captivity to Kashchey the Immortal.
—Bazza the Beast