If ever you are stuck for ideas, look to Greece.
In the ancient myths and legends of Greece, there are intriguing prophecies, clever generals, jealous deities, inventive punishments – and frightening beasties. Herodotus is a favourite of mine for such tales, but there’s plenty to draw from. The plays of Euripides and Sophocles, or for a more comedic bent, Aristophanes. The histories of Thucydides and Xenophon, the biographies of Plutarch.
But the best source for today’s topic is Apollodorus and his Library of Greek Mythology, in which is told the story of the Minotaur.