Brüderchen und Schwesterchen (TV)

After Brüderchen and Schwesterchen (German for young/dear brother viz. sister's mother's death, their dad finds a new wife and mother for them. But she's a witch, who poisons him and reduces the siblings to slaves for her and their nasty step-sister. After an escape attempt, the witch transforms the boy into a deer. When he finally has a run in the wood, the young king's hunting party wounds it badly. By tracking his prey, the ruler discovers and falls in love with his sister. The whole family moves into the royal palace, where the witch tries new tricks. - IMDb