Thersites, son of Agrius, was the ugliest of all the Greeks in the war of Troy, lame, hump-back and impudent and was hateful to Achilles and to Odysseus because of his insolent behaviour (Il. 2.212-271). Homer calls him "akritomythos" (= "of reckless speech") (Il. 2.246).
The son of Agrius. He was the most deformed man and impudent talker among the Greeks at Troy. According to the later poets he was killed by Achilles, because he had ridiculed him for lamenting the death of Penthesilea, queen of the Amazons.
Perseus: Harry Thurston Peck, Harpers Dictionary of Classical Antiquities (1898)