Minotaur, the Wild Beast of Crete.

King Minos sacrifices the 'required' virgins to the Minotaur. As his wife lies dying, she confesses that her daughter has a twin she has secreted to avoid giving one of the girls to the Minotaur. The daughter raised by Minos tries to have her twin killed, but failing in her first attempt, continues to try to have her given to the Minotaur. Theseus, the Greek hero, tries to prevent it.