Docon was a Ionian champion who took part in the second tournament in Myceane Arena. He was a Blacktongue and was one of the conspirators who planned to kill King Lycomedes in order to claim Myceane for Blacktongues.
At the final fight of the tournament, when Achilles unexpectedly appeared, Docon protested and send himself some men for help him. Jason and Achilles slew them all, including Docon. Meanwhile Patroclus tried to kill Lycomedes in his seat but he dodged and smashed Patroclus's head with his mace.
Jason met Docon again at Tartarus where Jason erased him from underworld by killing him there.