Nessus

I've never seen the Disney film, Hercules, but I do know the actual myth. In Greek mythology, Nessus was a centaur who offered to help Heracles and his wife, Deianeira, cross a river. However, Nessus was entranced by Deianeira's beauty, so he decided to take her for himself. Heracles shot an arrow (poisoned by the Hydra's venom) at the centaur before anything bad could happen to his wife. While he was dying, Nessus tricked Deianara into making
a tunic mixed with his (now poisoned) blood for her husband to wear, telling her it would keep her husband faithful. This would eventually lead to the "death" of the celebrated hero.

In the Divine Comedy, Nessus is given a more nicer (but still sadistic) personality, where Chiron tasks him to help Dante & Virgil cross a BOILING RIVER OF BLOOD. The two poets and the centaur actually get across with no issue.