Great Scuttler (5e Creature)
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Large monstrosity, unaligned
Amphibious. The scuttler can breathe air and water.
Surprise Attack. If the scuttler surprises a creature and hits it with an attack during the first round of combat, the target takes an extra 10 (3d6) damage from the attack.
Multiattack. The scuttler uses its Brilliant Antennae. It then makes two attacks with its claws.
Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage, and the target is grappled (escape DC 14). The scuttler has two claws, each of which can grapple only one target. Miss: The scuttler can take the Disengage action as a bonus action and move up to 10 feet.
Great scuttlers are larger and stronger than ordinary scuttlers. A great scuttler has a long pair of antennae that glow with strange light. Other scuttlers cannot resist this light, and as the great scuttler moves its antennae, it sends wordless orders to its minions, which obey them implicitly.