Celestial Stag

Charge. If the stag moves at least 20 feet straight toward a target and then hits it with a ram attack on the same turn, the target takes an extra 7 (2d6) damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.

Tireless (recharges once per long rest). The stag requires no food, drink or rest. It can move at three times its normal speed overland and perform three times the usual amount of labor. However, the stag is not protected from fatigue or exhaustion caused by a magical effect. 

Undead Fortitude. If damage reduces the stag to 0 hit points, it must make a Constitution saving throw with a DC of 5+the damage taken, unless the damage is from a critical hit. On a success, the stag drops to 1 hit point instead.

Ram. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage.

Heart Sight. The stag touches a creature and magically knows the creature's current emotional state. If the target fails a DC 10 Charisma saving throw, the stag also knows the creature's alignment. Celestials, fiends, and undead automatically fail the saving throw.

Hooves. Melee Weapon Attack: +5 to hit, reach 5 ft., one prone creature. Hit: 8 (2d4 + 3) bludgeoning damage.