In Greek and Roman mythology, Cacus was a fire-breathing giant and the son of Vulcan. He was killed by Hercules after terrorizing the Aventine Hill before the founding of Rome.
Hercules killing the fire-breathing Cacus, engraving by Sebald Beham (1545)
Hercules and Cacus by Baccio Bandinelli (1525–34); (Palazzo Vecchio, Florence)
Vulcan is the god of fire including the fire of volcanoes, deserts, metalworking and the forge in ancient Roman religion and myth. He is often depicted with a blacksmith's hammer. The Vulcanalia was the annual festival held August 23 in his honor. His Greek counterpart is Hephaestus, the god of fire and smithery. In Etruscan religion, he is identified with Sethlans.
Vulcan, wearing an exomis (tunic) and pilos (conical hat), sculpted by Bertel Thorvaldsen
A fresco of Vulcan-Hephaestus in Pompeii
Andrea Mantegna: Parnassus (detail): Vulcan, god of fire (1497)
Punishment of Ixion: in the center is Mercury holding the caduceus and on the right Juno sits on her throne. Behind her Iris stands and gestures. On the left is Vulcanus (blond figure) standing behind the wheel, manning it, with Ixion already tied to it. Nephele sits at Mercury's feet; a Roman fresco from the eastern wall of the triclinium in the House of the Vettii, Pompeii, Fourth Style (60–79 AD).