The Storyteller (1988)

S1E6 The Three Ravens

Having enchanted the widowed king into marrying her, a wicked witch realizes his children pose a threat to her newfound authority. She discovers their hidden refuge and transforms the three princes into ravens. The ravens warn the princess that unless she remains silent for three years, three months, and three days, they will be trapped in their bird forms forever. This tale is inspired by an old German folk story.