Laocoön.

     A prince of Troy and brother of Anchises, Laocoön was a priest of Apollo (or of Poseidon). During the Trojan War, he warned the Trojans of the dangers of the wooden horse—left by the Greeks outside the city—and flung his spear into its side. As he was sacrificing to Poseidon, he and his two sons were attacked by sea serpents and crushed to death. This was taken by the Trojans as a sign of the gods’ punishment and confirmed their decision to pull the horse within the city walls.
     The subject is best known through the statuary group depicting Laocoön and his sons strangled by the serpents, carved in Rhodes ca.25 BCE and now in the Vatican Museum. (=LaocoonANCIENT_Vatican) Most postclassical representations of Laocoön are derived from this important sculpture.

     Further Reference. Bieber, Margaret. 1942. Laocoôn: The Influence of the Group Since Its Rediscovery. Rev. ed. Detroit: Wayne State University Press.
    See also
Trojan War, General List, Wooden Horse.