The Bonnacon is a mythical animal from Macedonia

Some investigators feel that the Bonnacon’s lack of body hair is a result of the most biologically compelling aspect of the creature, its unique self defense mechanism. In Pliny the Elder’s notes of the Bonnacon, he described that the creature’s horns curved back in a manner that would render them useless in a fight and in order to save itself the creature would be forced to run away. Pliny tells us that as the creature retreats it emits a trail of dung that would sometimes cover a distance as long as three furlongs, or approximately 3 acres. Any contact with the creatures dung would scorch the pursuer like a sort of fire. This napalm like excrement may have given rise to legends that the Bonacon also had the ability to breathe fire, much like the European Dragon, making this creature deadly at both ends

Naturalis Historia – Pliny the Elder 77 AD

 The Bonnacon – publicdomainreview.org