The Fire Breather was a huge leviathan with tough hide and natural chemicals that was manipulated by the Yuuzhan Vong for use as a heavy support organism.
These deadly war beasts had flexible proboscises that spewed streams of gelatinous flame, pores that exhaled anti-laser aerosols, and hides thick enough to withstand all but a blast from a turbolaser.
The liquid flame was created through a unique chemical reaction caused by the mixture of methane, hydrogen sulfide, and a mysterious substance deep within the guts of the Fire Breather. The beasts were often deployed for clearing out entrenched enemy positions.
Fire Breathers were first encountered on Gyndine where they burned the forests and caused the lakes to boil. According to most reports, the Fire Breathers acquired swamp gas from the planetMimban in the Circarpous Major system, prior to invading Gyndine. Fire Breathers also appeared with an invasion on Artorias.[1]