|Status:||Alive (as of 1878)|
Balios is a black horse owned by the Shadowhunters of the London Institute in the 1870s, cared for by Thomas Tanner, and later his brother, Cyril. Along with Xanthos, both horses were named by Will Herondale after the immortal horses of Achilles. Both are said to be magical horses; stronger and faster than ordinary ones. Out of the two, Balios was Will's favorite.
Balios was the horse Will rode from London to Cadair Idris in Wales in 1878. While Balios did not tire quickly, he still needed rest, thus Will made some stops along the way to allow Balios to feed, drink, and sleep. Shortly after arriving in Wales, however, Balios momentarily collapsed on the road, after days of relentless riding. Will managed to pull Balios up on his feet and walked their way to a town with a public house where Balios was taken care of by a stable-boy.
After a long rest, however, the village was attacked by Mortmain's demonic automatons, making Balios panic and run from Will. Shortly after, Balios kicked away an automaton that attacked Will, and the two rode away to safety. Having recovered, Balios was able to take Will to his destination. Once there, Will told Balios to wait for him, and that if he did not return, he should return to the Institute without him. Understanding, Balios tried to object and stop Will, to no avail.
- While Balios and Xanthos are not easily spooked by noise, Balios is clearly bothered by shouting.