A Lithuanian fairy tale, this version is from Tales of The Amber Sea, compiled and translated by Irina Zheleznova in 1974.
Long, long ago, in times gone by, there lived an old man and an old woman. They had twelve sons and three daughters the youngest of whom was called Spruce.
One summer evening the sisters went for a bathe. They swam and splashed about, and, having had their fill of it, climbed out on shore and reached for their clothes. Spruce looked, and there, coiled up in the sleeve of her shift, she saw a grass snake! What was she to do? Her older sister snatched up a stake in order to chase it out but the grass snake turned to Spruce and said in a human voice:
“Spruce my dear, promise to marry me and then I’ll crawl out myself.”