From the handbook (Page 15):
Built by Academy
Mobile unit - Combat - Weapon: Melee Tusk Attack & Cannon.
Ever logical and always willing to acknowledge the strengths of their enemy, the Beast Rider is a relatively recent addition to the arsenal of the Creon's might. This was formerly a weapon used by the kingdom of Jimarna during its protracted war with Creon. A large battle beast carries a skilled artillery specialist in a covered howdah. The effect of the Beast Rider is as psychological as it is practical. Enemies who are feint of heart have been known to flee in terror before these impressive creatures.