Thick spines like the flanges of a royal crown bristle all across the surface of this strangely large golden sea urchin.
Speed 10 ft.
Great diadem urchin venom is shockingly painful and feels acidic at the moment of contact—though the worst of the pain fades after a moment. The save DC is Constitution-based.
A great diadem urchin's spines can swivel to face any approaching creature. Any creature that attacks a great diadem urchin with an unarmed strike or a natural attack, or any Large or smaller creature that attacks with a one-handed weapon or light weapon, is automatically attacked by the hunter urchin's spines as an immediate action. If the spines hit, they can poison the target as well.