Ancient Crawler (5e Creature)
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Huge construct, neutral
Damage Resistances cold, fire; slashing, piercing, and bludgeoning from nonmagical attacks not made with adamantine weapons
Immutable Form. The crawler is immune to any spell or effect that would alter its form.
Magic Weapons. The crawler's weapon attacks are magical.
Trampling Charge. If the crawler 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 16 Strength saving throw or be knocked prone. If the target is prone, the crawler can make another attack with its hooves against it as a bonus action.
Multiattack. The crawler makes three melee attacks: one with its bite, and two with its hooves.
Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 12 (1d12 + 6) piercing damage.
Hooves. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 17 (2d10 + 6) bludgeoning damage.
Ancient crawlers are the relics of ancient creatures that were banished to the Underdark long ago, and shortly after were deactivated and buried in massive underground dungeons. They vaguely resemble horses, though they are much larger and stronger, and never tire. Jet black plates of metal adorn them, and their resistance is incredible. Some time ago, some started to reactivate, but they usually keep to their dungeons, protecting the vestiges of an empire they do not know has fallen.
Constructed Nature. An ancient crawler doesn't require air, food, drink, or sleep.