Clockwork Dreadnought

Shutdown. If targeted by dispel magic, the dreadnought must succeed on a Constitution saving throw against the caster’s spell save DC or fall unconscious for 1 minute or until it takes any damage.

System Overload. If the Dreadnought takes lighting damage it must succeed a DC 15 Constitution saving throw or take disadvantage on its next attack if it rolled a 10-14 if it rolled under a 9-1 it does not know friend from foe and attacks the 3 nearest creature(s) on its next turn  

Unusual Nature. The dreadnought doesn’t require air, food, drink, or sleep.

Multiattack. The dreadnought can make one Power Claw attacks, and two Arrow autocannon attacks.

Power Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) force damage.

Arrow autocannon. Ranged weapon attack: +4 to hit, range 120 ft., one target. Hit: 7 (1d10 + 2) piercing damage.

Anti-missile defense: Whenever hit by a non-magical ranged attack, the Dreadnought can use its air-defense system to target the incoming missile if it is small or smaller size. When it does so it reduces the damage by 1d10+3