Orthrus

The orthrus is a large two-headded dog, capable of breathing fire.

Source
Orthrus is the offspring of Typhon and Echidna. The Othrus' siblings are the Hydra, Cerberus, Sphinx and Chimera. The earliest mention is by Hesiod around 700 BC.

Media
The orthrus appear in the following media:

Games

 * Titan Quest
 * Titan Quest