The Seventh Labour: Capture the Cretan Bull
Some Greek stories call the Cretan Bull the bull which fathered the minotaur, the half-man, half-bull monster that was later killed by Theseus. Either way, the Cretan Bull rampaged across Crete.
The king of Crete, King Minos, offered Heracles help in capturing the bull, but Heracles thought he was doing well with the labors and refused because of pride. Alone, he snuck up behind the bull and using his great strength strangled the bull (although he did not kill it). He returned the bull to Marathon, where it was released and became the Marathon Bull.