Short answers, pulled from the story.
Hellenistic art is generally taken to begin with the death of Alexander the Great in 323 BC. It ended with the Roman conquest of the Greek world, a process largely complete by 146 BC when the Greek mainland fell, and definitively concluded in 30 BC with the Roman conquest of Ptolemaic Egypt following the Battle of Actium.
Among the best-known works of Hellenistic art are the Laocoön and His Sons, the Dying Gaul, the Venus de Milo, and the Winged Victory of Samothrace. The Laocoön was discovered in Rome in 1506 and seen immediately by Michelangelo.
Alexander the Great traveled with three artists: Lysippus the sculptor, Apelles the painter, and Pyrgoteles the gem cutter and engraver.
Pergamene Baroque is a sculptural style developed at Pergamon under the Attalid kings, characterized by three-dimensional compositions, anatomical hyper-realism, and intense depictions of suffering and violence. The Great Altar of Pergamon, decorated under Eumenes II (197-159 BC) with a gigantomachy frieze stretching 110 metres, is its most monumental example.
Sosos of Pergamon, active in the second century BC, is the only mosaic artist cited by name in Pliny the Elder's writings, making him the single named personality in the craft. His works include the Unswept Floor, now in the Vatican museum, and the Dove Basin, known through a copy found at Hadrian's Villa and now held at the Capitoline Museum.
The Stag Hunt Mosaic is a pebble mosaic from a wealthy home in Pella, dated to the late fourth century BC. It was signed by an artist named Gnosis, whose signature reads Gnosis epoesen, making it the first known signed work by a mosaicist in history.