Ahu-Nixta Cataphract

Clockwork Encasement. The creature within the machine is a somewhat shapeless mass, both protected and given concrete manipulators by its armor. The clockwork armor has a variety of manipulators that the ahu-nixta can use to attack or to interact with objects outside of the armor. When the ahu-nixta is reduced to 0 hp, its clockwork armor breaks and the ahu-nixta exits it. Once out of its armor, the creature's pulpy mass no longer receives the benefits of the listed Damage or Condition Immunities, except for psychic and prone. Without its clockwork armor, the ahu-nixta has the following statistics: AC 12, hp 37 (5d10 + 10), Strength 9 (-1), and all its modes of travel are reduced to 20 feet. In addition, it has no attack actions, though it can still cast its spells. The ahu-nixta's body can form eyes, mouths, and grabbing appendages. Its grabbing appendages can pick up objects and manipulate them, but the appendages can't be used for combat. The ahu-nixta's extra appendages can open and close glass-covered viewing ports in the clockwork armor, requiring no action, so it can see and interact with objects outside the armor. The ahu-nixta can exit or enter its clockwork armor as a bonus action.

Immutable Form. The ahu-nixta's clockwork armor is immune to any spell or effect that would alter its form, as is the creature that controls it as long as the ahu-nixta remains within the armor.

Innate Spellcasting. The ahu-nixta's innate spellcasting ability is Intelligence (spell save DC 15, +7 to hit with spell attacks). The ahu-nixta can innately cast the following spells, requiring no material components: At will: fear, fire bolt (2d10), telekinesis

Multiattack. The cataphract makes three melee attacks. It can cast one at will spell in place of two melee attacks. Alternatively, it can use its Arcane Cannon twice.

Whirring Blades. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (3d4 + 5) slashing damage, and the target must succeed on a DC 15 Dexterity saving throw or take 5 (2d4) slashing damage at the start of its next turn.

Pronged Scepter. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 12 (2d6 + 5) piercing damage.

Bashing Rod. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 16 (2d10 + 5) bludgeoning damage

Arcane Cannon. Ranged Spell Attack: +7 to hit, range 100 ft., one target. Hit: 18 (4d8) force damage, and the target must succeed on a DC 15 Strength saving throw or be knocked prone.