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.

In mythology and fantasy, a fire-breathing monster is a monster with the ability to shoot fire from its mouth. The concept of a fire-breathing monster is shared by various mythological traditions throughout history, and is also a common element of monsters in the fantasy genre, especially dragons, which are almost always given the ability to shoot fire, or some other type of breath-based attack. The origins of this power may vary, from magic to a biological explanation similar to an organic flamethrower.