Firebreather

Firebreather is a Level 50 quality one-handed sword that has a chance on hit to deal additional  damage.

Source
This item drops from:
 * Hazzas in The Temple of Atal'Hakkar
 * Morphaz in The Temple of Atal'Hakkar
 * Weaver in The Temple of Atal'Hakkar
 * Dreamscythe in The Temple of Atal'Hakkar