Basilisk Steed

Petrifying Gaze (Recharge 5-6). Unlike regular Basilisk's, a Basilisk Steed has to activate it's petrifying gaze and it must recharge this ability. 

If a creature starts its turn within 15 feet of the basilisk and the two of them can see each other, the basilisk can force the creature to make a DC 14 Constitution saving throw if the basilisk isn't incapacitated.

On a failed save, the creature magically begins to turn to stone, their speed decreases by 10 ft and they cannot take reactions. - Turn 1

It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is restrained until freed by the lesser restoration spell or other magic. - Turn 2

At the end of it's next turn they must repeat the saving throw. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic. - Turn 3

On a failed save, the creature magically begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. 

A creature that isn't surprised can avert its eyes to avoid the saving throw at the start of its turn. If it does so, it can't see the basilisk until the start of its next turn, when it can avert its eyes again.

Unlike regular Basilisk's, a Basilisk Steed's gaze does not affect itself or those it's owner considers allies. 

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:  6 (1d6+4) bludgeoning damage and  6 (1d6+4) poison damage.