Thracian Horse (5e Creature)
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Large monstrosity, unaligned
Flesheater. The horse has advantage on melee attack rolls against any creature that doesn't have all its hit points. After reducing a humanoid to 0 hit points, the horse instead has disadvantage on initiative and attack rolls until it completes a short or long rest.
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 as a bonus action.
Multiattack. The horse makes two attacks: one with its bite and one with its hooves.
Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 12 (2d8 + 3) piercing damage.
Hooves. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) bludgeoning damage.
Fire Breath (Recharge 5-6). The horse exhales fire in a 15-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw, taking 16 (3d10) fire damage on a failed save, or half as much damage on a success.
Feeding only on flesh, these savage wild horses make fearsome mounts for those who can manage to control their tempers. They can be temporarily calmed if fed the body of a humanoid, and are also made much less dangerous if they can be muzzled.