Trivia:

At one point a song floats over the soundtrack: "My mother, she killed me, my father, he ate me, and my little sister, my bones she kept, what a pretty bird am I!" This comes from another Grimm fairy tale, "The Juniper Tree,"widely considered by scholars as the darkest of all their tales. In it, a spiteful mother beheads her stepson and blames it on her daughter. She then cooks the corpse and feeds it to his husband, as the daughter picks up the bones from under the table and plants it under a juniper tree on the family's garden. A small bird appears from the grave, singing the song in question while picking a pair of new shoes, a gold chain and a mill stone, and then carries them to the house. The bird then gives the shoes to the daughter, the chain to the father and drops the stone on the stepmother, killing her. As she dies, the bird turns into a boy again and the story ends. The film borrows some thematic elements this tale.