Armor Class 20 (natural armor)
Hit Points 207 (18d10 + 108)
Speed 40 ft.
Skills Perception +7, Stealth +8, Survival +7
Damage Resistances cold, lightning, necrotic, thunder
Damage Immunities poison, psychic, [object Object]
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned, stunned
Senses blindsight 30 ft., darkvision 60 ft., passive Perception 17
Languages understands Modron and the language of its owner but can't speak
Challenge 16
Magic Resistance. The steel predator has advantage on saving throws against spells and other magical effects.
Unusual Nature. The steel predator doesn't require air, food, drink, or sleep.
Multiattack. The steel predator makes one Bite attack and two Claw attacks.
Bite. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 18 (2d10 + 7) lightning damage.
Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 7) force damage.
Stunning Roar (Recharge 5–6). The steel predator emits a roar in a 60-foot cone. Each creature in that area must make a DC 19 Constitution saving throw. On a failed save, a creature takes 33 (6d10) thunder damage, drops everything it's holding, and is stunned for 1 minute. The stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. On a successful save, a creature takes half as much damage and isn't stunned.
Mordenkainen Presents: Monsters of the Multiverse, p. 232