Beached Thing

Ambush Predator. If the beached thing hits a surprised creature with a Grasping Hands attack, it can perform Submerge as a bonus action.

Echolocation. The beached thing's blindsight does not work while the beached thing is deafened.

Timefall. The area within 500 feet of the beached thing is covered in an endless rain that rises as high as the clouds. Creatures within the rain with no physical armor (i.e. not force armor such as mage armor) that are exposed to the timefall age 1d6 years at the start of their turn while they are in the timefall. Beached things are immune to this effect. Creatures in nonmagical armor that spend a cumulative amount of time exposed to timefall equal to 1 minute gain a permanent -1 penalty to their armor as it ages beyond use. If this reduction reduces the base AC of the armor to 10, it is permanently destroyed. Objects worn or carried by a creature are also affected by the timefall. Objects and structures that take damage while exposed to timefall take double the normal amount of damage from all effect, which stacks with the Siege Monster feature.

To the Other Side. The beached thing automatically succeeds on all saves against being banished, unless an optional material component of 1 cup of the blood of a repatriate is consumed for the material component, in which case the beached thing automatically fails the saving throw and is immediately turned into a petitioner of its plane.

Visions of Death. The beached thing is always magically invisible. This can be disabled for 1 minute with any effect which dispels magic, such as dispel magic or when in the area of an antimagic field. Repatriates who are still children are capable of seeing beached things without assistance.

Voidout. When a creature that is not an undead is reduced to 0 hit points by damage dealt by the beached thing, it dies. If the creature's body is not burned to ashes within 1 day of its death (which can be extended by spells such as gentle repose) or it is not resurrected before that point, it will rise as a beached thing and the body of the creature will explode, dealing 200 necrotic damage to any creature within 1 mile of the creature. Any creature which dies in this explosion also is raised as a beached thing in 24 hours, but does not trigger the voidout feature. A creature turned into a beached thing cannot be resurrected even by a wish spell until the beached thing it became is killed.

Multiattack. The beached thing makes 2 Grasping Hands attacks. It can replace any number of Grasping Hands attacks with Submerge attacks.

Grasping Hands. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit 27 (3d8 + 5) bludgeoning damage plus 5 (1d8) necrotic damage, and the target is grappled (escape DC 16). While the beached thing has grappled a creature, the area within 10 feet of the beached thing counts as difficult terrain as viscous black tar bursts from the body of the beached thing.

Submerge. The beached thing makes a Strength (Athletics) check with advantage against a creature it has grappled. On a success, the creature is restrained, submerged into the ground in a pool of tar, and starts suffocating. The creature can make a Strength (Athletics) check as an action at the end of its turn to break free from the tar, ending the grappled and restrained conditions and no longer suffocating. If the beached thing is killed, the creature can spend 5 feet of its movement on its turn to leave the tar, falling prone.