The Three Royal Children (2019)

King Alexander is happy with his commoner-born queen Marie, but their three children are puppies (actually switched at the queen mother Eliza's orders by chamberlain Corbinian, who put each in a basket in the river), then she dies mysteriously. 12 years later, the king still mourns, refusing to remarry any princess picked by his mother. Then on a hunting trip, he meets Theo, Fritz, and Lotte, three foundlings--who greatly resemble his late wife--raised by farmer Hank and his wife. Eliza decides to dispose of the princes by tricking them into attempting to seek infallible answers from the bird of truth, which requires two equally magical gifts, each likely to be transformed at failure into rocks.