We move as one. While mounted in combat. You can use the speed of your mount as movement on your turn.

We fight as one. You can forgo one of your (action) attacks to allow your mount to attack. (This includes any special attack granted by your cavalier features) Also, while mounted, you can make any spell cast that targets only you also target the mount.

Trampling Charge. If the horse moves at least 20 feet straight toward a creature and then hits it with a hooves attack on the same turn, that target must succeed on a DC 14 Strength saving throw or be knocked prone. If the target is prone, the horse can make another attack with its hooves against it.

Spiritually connected. When you or your mount takes damage, you can split the damage between the two of you equally. Also if your mount would take damage, you can throw yourself in front of the attack instead; taking the full damage your mount would have suffered. Also, when the mount drops to 0 hit points it disappears until resummoned.

Immutable form. This creature cannot be affected by any kind of shapechanging spells or magical effects.

*Can be summoned once per day

Hooves. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:  (2d6 + 4) bludgeoning damage.