I bought The Book of Beasts from the Cloisters gift shop today. Hilarity ensues.
On the Bonnacon (aka bison) - “The horns are curled round upon themselves with such a multiple convolution that if anybody bumps them he does not get hurt. But however much his front end does not defend this monster, his belly end is amply sufficient. For when he turns to run away he emits a fart with the contents of his large intestine which covers three acres. And any tree that it reaches catches fire. Thus he drives away his pursuers with noxious excrement.”
Translated by TH White from a Latin 12th century bestiary