Giant Starfish (5e Creature)
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Large beast, unaligned
Hold Breath. While out of water, the starfish can hold its breath for 1 hour.
Regeneration. The starfish regains 20 hit points at the start of its turn. If the starfish takes acid or fire damage, this trait doesn't function at the start of the starfish's next turn.
Water Breathing. The starfish can breathe only underwater.
Pseudopod. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 10 (2d8 + 2) bludgeoning damage.
Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 14 (2d12 + 2) bludgeoning damage. If the target is a creature, it is grappled (escape DC 18). Until this grapple ends, the target is restrained.
Swallow. The starfish opens its mouth and makes one melee attack against a Medium or smaller target it is grappling. If the attack hits, the target is also swallowed, and the grapple ends. While swallowed, the target is blinded and restrained, it has total cover against attacks and other effects outside the starfish, and it takes 12 (3d8) acid damage at the start of each of the starfish's turns. A starfish can have only one creature swallowed at a time.
Starfish cannot die of old age, and due to this, it is possible for them to live nearly forever. Occasionally, a starfish is fortunate enough to live for hundreds of years, continually growing the entire time until they become several times the size of the average adult starfish. Their larger size increases the size of potential prey, meaning that an unlucky adventurer could become a meal for this ocean dweller.