This ancient work's artist is unknown. The only hint we have as to who the creators of this piece are is a reference by Pliny the Elder naming three artists who are said to have worked on this together.
We do however know what's happening in this sculpture, as disconcerting as it is. There is a forever lost play by Sophocles that we have references to in secondary sources that spoke of the story of Lacoon and his sons. Lacoon was a Trojan who did not believe the ruse of the wooden horse left for them by the Greeks. He went to stab it with a spear and Athena, in defense of the Greeks, sent serpents to attack him. Thinking this was a sign to accept it (as it was, though for an evil outcome), the Trojans welcomed it in, to their demise.