NESSUS was a centaur. He met Hercules on the banks of the flooded river Evenus, as he prepared to cross with Dejanira. Nessus ferried her across, then tried to rape her. Hercules shot him with one of the arrows dipped in the blood of the Lernean Hydra. As he lay dying, Nessus advised Dejanira to collect some of his blood and to use it as a means of regaining Hercules's love, if she ever needed to. Dejanira followed his advice after Hercules brought Iole home to live with them. She sent him a shirt smeared with the blood as he prepared to sacrifice to Jupiter. When Hercules put the shirt on, the poison burned into his flesh. In his agony, Hercules commanded a pyre to be built, the fire lit; then he climbed onto it. Jupiter caught him up and placed him among the constellations (Met IX.98-272; OM IX.347-452, 487-872). The Confessor tells the story of Nessus, Hercules, and Dejanira to illustrate the work of Faussemblant, Confessio Amantis II.2145-2307.

The Monk says that some blame Nessus for Hercules's death and excuse Dejanira, MkT 2119-2128. [Dianira: Ercules: Yole]

The name occurs medially, MkT 2128.