Hercules fighting Acheloos transformed into a snake | Louvre Museum | Paris

"The subject is taken from Ovid's Metamorphoses: Achelous was the rival of Hercules for the love of Deianira; during the fight, Achelous was transformed into a serpent but was defeated by Hercules. Thus Hercules made himself loved by Deianira Subsequently, trying to rekindle his love for her, Deianira offered Hercules a tunic impregnated with the blood of Nessus which, instead of being a love potion, turned out to be a burning poison."