Gargantuan Construct, Unaligned

Armor Class: 5 

Hit Points: 656 HP (33d20+330)

Speed: 30 ft. (Special)

STR 30/+10

DEX 1/-5

CON 30/+10

INT 3/-4

WIS 4/-3

CHA 1/-5

Damage Immunities. Poison, Psychic, Piercing

Damage Resistances: Slashing

Damage Vulnerabilities: Thunder

Condition Immunities: Blinded, Charmed, Exhaustion, Frightened, Incapacitated, Paralyzed, Petrified, Poisoned, Prone, Stunned, Unconscious 

Senses: Blindsight 120 ft, Passive Perception 7

Languages: –

Challenge: 12

Proficiency Bonus: +4

Living Fort. The  Walking Fortress is a giant animated stone structure which occupies a 60 ft. by 60 ft. space in combat. Its unique nature also gives it additional mechanics and interactions. 

• Legs and Battlements. Most parts of  the Walking Fortress do not touch the ground, but are instead from up to 15 ft. above the surface. Creatures are able to move under these parts without any restrictions or penalty to their movement if they are appropriately sized for it.
  • standing behind the battlements of the Walking Fortress provides ½ cover against creatures on the same elevation level and ¾ cover against creatures on lower elevation levels. 
  • The only parts of the Walking Fortress that are touching the surface are its massive four legs, which occupy the corners of the creature’s space and are 15 ft. by 15 ft. in size.
    • These legs cannot be moved through, but they can be climbed onto to reach the upper parts of the Walking Fortress. Unless the Walking Fortress is restrained or otherwise unable to move, any creature that starts its turn climbing on it, or that attempts to climb it during their turn must make a DC 10 Dexterity (Athletics) saving throw, falling and being knocked prone on a failure.
    • The legs can provoke Attacks of Opportunity. 
• Stone Structure. If a feature grants extra damage against objects, that extra damage applies to the Walking Fortress as well. 
• Lumbering Tower. The Walking Fortress walks slowly and only manages to do a single long step each turn, one that can be easily dodged and maneuvered around.
  The Walking Fortress moves only at the start of its turn, and only to the space designated at the end of its previous turn. All other creatures that see the fortress know where it intends to move. If any creature were to share space with one of the legs of the fortress after it moves, they must make a DC 15 Dexterity saving throw, taking 20d10 bludgeoning damage on a failure and being moved to the nearest unoccupied space. On a success, the creature only takes half damage.  

Enchanted Walls. If the Walking Fortress takes 30 or less damage from an effect or an attack, the damage is reduced to 0.

Stonecore. On the top of the Walking Fortress, is embedded a small pulsating crystal that powers the structure. This Stonecorel shares Hit Points with the fortress, and it is the only part of the Walking Fortress that doesn’t benefit from the Enchanted Walls feature and is also vulnerable to all damage types.
However the Stonecore has a circular protective magical barrier with a 10 ft. radius around itself, and it cannot be damaged by attacks or effects originating from outside the barrier. 

Stone Soldiers. The Walking Fortress is unable to attack and cannot personally deal with any creatures that climb onto it, but there are three animated stone statues on its body that are capable of protecting it and serving as its sources of offensive power. 

These Stone Soldiers have the following features and statistics 

• 100 Hit Points, AC 15, Medium size
• They each have their separate Hit Points not shared with the Walking Fortress
• They have the same Condition Immunities as the Walking Fortress and are immune to Poison and Psychic damage
• They share initiative with the Walking Fortress and they can only use Actions depending on actions used by the Walking Fortress.
• Their bodies are fused with the Walking Fortress and they don’t have any movement speed and cannot be moved by any effects except for Stonewarp. 
• They share the same Ability Scores as the Walking Fortress, except their Strength and Constitution scores are 18/+4
• They are reduced to 0 Hit Points if the Walking Fortress is reduced to 0 Hit Points
• If a Stone Soldier is killed, it regenerates after 24 hours

Actions.

• Rain of Spears. All Stone Soldiers make a Stone Javelin attack.
• Stonewarp. All Stone Soldiers can teleport to any unoccupied space on the body of the Walking Fortress. They can appear at any angle and from any part, including the underside and legs of the Walking Fortress, as long as they remain connected to it by touch. 
• Stone Javelin (Made by a Stone Soldier). Melee or Ranged Weapon Attack: +8 to hit, reach 5 ft., or range 600 ft, one target. Hit: 14 (4d6+4) Piercing Damage and the creature must make a DC 16 Strength saving throw, being knocked prone on a failure.