Animated Castle

Immutable Form. The colossus is immune to any spell or effect that would alter its form.

Magic Resistance. The colossus has advantage on saving throws against spells and other magical effects.

Siege Monster. The colossus deals double damage to objects and structures.

Towering Tremors. Any enemy outside the colossus that starts its turn within 30 feet of it must succeed on a DC 18 Dexterity saving throw or be knocked prone.

Multiattack. The colossus makes three attacks — one with its slam and two with its ballista turrets — and then uses Stomp.

Slam. Melee Weapon Attack: +8 to hit, reach 20 ft., one target. Hit: 29 (3d12 + 10) bludgeoning damage, and the colossus can push the target up to 20 feet away from it.

Ballista Turret. Ranged Attack: +8 to hit, range 300 ft., one target. Hit: 18 (4d8) piercing damage.

Stomp. The Castle stomps one of its feet at a point on the ground within 20 feet of it. Any creature in a 20-foot-radius, 20-foot-high cylinder centered on this point must succeed on a DC 18 Dexterity saving throw or take 20 (4d10) bludgeoning damage and fall prone. Until the colossus uses its Stomp again or moves, the creature is restrained. While restrained in this way, the creature (or another creature within 5 feet of it) can use its action to make a DC 26 Strength check. On a success, the creature relocates to an unoccupied space of its choice within 5 feet of the colossus and is no longer restrained.

Structures, as well as nonmagical objects that are neither being worn nor carried, take the same amount of damage if they are in the cylinder (no save).

Animated Minions (Recharge 5–6). The Castle projects from every window and door a flood of Animated Furniture in a 30-foot cone, each creature in the cone must make a DC 18 Dexterity saving throw, taking 10 (2d10) bludgeoning damage on a failed save, or half as much damage on a successful one. Then 4d4 Animated Tables, and 4d4 Animated Chairs are summoned within that 30-foot cone.