Mossback Steward

Gargantuan monstrosity, Unaligned

Armor Class

17 (natural armor, 22 while in its shell)

Hit Points

227 (13d20+91)

Speed

walk 20 ft.

Saves

Str +12, Con +10

Damage Immunities

poison

Condition Immunities

poisoned

Senses

darkvision 60 ft

Languages

understands Goblin but can't speak

Challenge

7

Amphibious

Mossback Steward can breathe air and water.

Massive Frame

Mossback Steward can carry up to 20,000 pounds of weight atop its shell, but moves at half speed if the weight exceeds 10,000 pounds. Medium or smaller creatures can move underneath Mossback Steward while it's not prone. Any creature under Mossback Steward when it falls prone is grappled (escape DC 18). Until the grapple ends, the creature is prone and restrained.

Actions

Bite

Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 28 (3d12 + 9) bludgeoning damage.

Shell Defense (Recharge 4-6)

Mossback Steward withdraws into its shell, falls prone, and gains a +5 bonus to AC. While Mossback Steward is in its shell, its speed is 0 and can't increase. Mossback Steward can emerge from its shell as an action, whereupon it is no longer prone.