Vulcan (mythology)
His festival, the Vulcanalia, was celebrated on August 23, when the summer heat made a fire hazard.  The people made bonfires, and threw live fish or small animals into the fires as animal sacrifice.  Vulcan was among the gods placated after the Great Fire of Rome in AD 64.  Also because of that fire, Domitian (emperor 81–96) established a new altar to Vulcan on the Quirinal Hill.  A red bull-calf and red boar were added to the sacrifices made on the Vulcanalia, at least in that part of town.