All the Cavalry rules apply to Monstrous Cavalry. In addition, the following rules apply:
Ranks
A unit of Monstrous Cavalry is required to be three or more models wide in order to have a complete rank.
Supporting Attacks
A Monstrous Cavalry model can make one supporting attack from the rider, and two from the mount. Monstrous Cavalry without a split profile can make up to three supporting attacks.
Special Rules
Monstrous Cavalry are subject to the following special rules: Fear, Impact Hits (1), Swiftstride.
Unit Strength
Monstrous Cavalry have a Unit Strength of 3.
Line of Sight
Monstrous Cavalry have a Line of Sight value of 3.