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 the tortoise 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.
Innate Spellcasting. Mossback Steward's innate spellcasting ability is Wisdom (spell save DC 15). It can innately cast the following spells, requiring no material components.
At will: friends
1/rest: suggestion, divination
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 the tortoise is in its shell, its speed is 0 and can't increase. The tortoise can emerge from its shell as an action, whereupon it is no longer prone.
Desolate badlands and soggy marshes are home to the ancient and massive horizonback tortoises of Eastern Wynandir. Nearly fifty feet from nose to tail, and with a habit of remaining stationary for long periods, a horizonback tortoise is easy to mistake for a low hill at a distance. But when these impressive creatures rise to begin their march, the sight inspires fear and awe in equal parts. An omnivore of incredible size, these scavengers prefer to feed on dead vegetation, but make use of…