Kabutops (5e Creature)
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Medium elemental, any alignment
Battle Armor. The kabutops takes half the damage from critical hits. This does not prevent any additional effects due to critical hits, such as that of a vorpal sword.
Swift Swim. The kabutops has advantage on Dexterity saving throws while partially submerged in water.
Multiattack. The kabutops makes two attacks, either with its Waterfall or its Stone Edge.
Waterfall. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 12 (2d8 + 3) bludgeoning damage.
Stone Edge. Ranged Weapon Attack: +6 to hit, range 60/180 ft., one target. Hit: 10 (2d6 + 3) bludgeoning damage.
Weak Armor. When the kabutops is struck by a critical hit, it can use its reaction to suppress its Battle Armor trait, taking full damage. When it does so, it has advantage on all attack rolls until the end of its next turn.