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.
Magic Weapons. The steel predator's weapon attacks are magical.
Multiattack. The steel predator makes three attacks: one with its bite and two with its claw.
Bite. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) piercing damage.
Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 7) slashing 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 27 (5d10) thunder damage, drops everything it's holding, and is stunned for 1 minute. On a successful save, a creature takes half as much damage. The stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Mordenkainen's Tome of Foes, p. 239