Heracross (5e Creature)
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Medium monstrosity, any alignment
Guts. The heracross has advantage on saving throws against being charmed or frightened, and while charmed or frightened, it has advantage on attack rolls.
Charge. If the heracross moves at least 20 feet straight toward a target and then hits it with a Megahorn attack on the same turn, the target takes an extra 14 (4d6) piercing damage.
Swarm. While it has 60 hit points or fewer, the heracross has advantage on attack rolls. In addition, it deals an extra 10 (3d6) damage to any target it hits with a melee attack.
Megahorn. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 36 (6d10 + 5) piercing damage.