In the Russian adaptation of the tale, called "The Enchanted Tsarevich," the prince is a three-headed winged snake demon, because if there's going to be a beast in this story, bitter Russian tradition demands that it be as bleak and horrific as the vodka-pickled depths of a Siberian winter. It starts when a merchant gets caught trespassing on the snake's land while picking a flower for his daughter, despite the fact that no part of that sentence makes any sense. The snake is furious, so the merchant agrees to send his daughter to live in the creature's magical castle, because what else could he do? He was trespassing.