Irrupt has horses that spawn on plains, like standard Minecraft – but you can also purchase horses in the tree top town of Tir Gire, as well as Minos.
To buy a horse, go to the stable. If you have enough currency, usually around $700, you can buy a horse. Horses do not come with saddles, but saddles can be purchased from the stable as well for under $30.
Once you have bought a horse, you may summon it. Type
/horse summon <horsetype>
to see any horses you may have. Most players rename their horse immediately. Type
/horse rename <horsetype> <newname>
If you leave your horse, it will despawn. Despawned horses are kept in a virtual stable, and may be summoned again at any time. You can keep a maximum of five horses in your stable.