The Fakastr are a race of semi-intelligent (akin to Wolves, Dolphins, and Chimps), massive, brutal bull-like creatures who grow limbs back after they have been hacked off, with a single exception: their horns.
The horns, when severed, remain alive and the Fakastr see it as a great dishonour to lose one. (They will grow back in two to three years) They always attempt to retrieve lost horns, escaping and travelling miles to seek out the owner and punish them. They can sense the presence of their horn and instinctively follow it, sometimes across continents…
The Fakastr are used by the people of Ichyria as entertainment. Fakastr arenas exist. In these fighting rings men contest the beasts and try to render them harmless. Of course the advantage is that any lost limbs grow back and the same Fakast can be used for many fights.
It is seen as a great prize for a Toreador-Warrior to hack off a horn of his Fakast, and Fakastr with no horns left are generally considered no good for the fighting ring.
They are somewhat even tempered creatures when used as beasts of burden. Treat them well and they will treat you well. (Though a few weeks every late winter when they go into heat, stand back). Even those used in the arenas will only fight people they recognize as warriors, so the handlers are normally fairly safe.