Giant Octopus

The giant octopus can breathe only underwater. It can hold its breath for 1 hour outside water.

Melee Weapon Attack: +5 to hit, reach 5 ft.. Hit: 10 (2d6 + 3) slashing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 13) from all eight tentacles. While Grappled, the target has the Restrained condition.

Trigger: The giant octopus takes damage while underwater. Response: The giant octopus releases ink that fills a 10-foot Cube centered on itself, and the giant octopus moves up to its Swim Speed. The Cube is Heavily Obscured for 1 minute or until a strong current or similar effect disperses the ink.