Bonnacon

The bonnacon (also called bonasus or bonacho) is a legendary creature described as a bull with inward-curving horns and a horse-like mane, that largely appeard in Medieval Bestiaries where they usually depict as having fur colored a reddish-brown or black. Because its horns were useless for self-defense, the bonnacon was said to expel large amounts of caustic feces from its anus at its pursuers, burning them and thereby ensuring its escape.