Clockwork Huntsmen

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

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

Explosive Core. The mechanism that powers the huntsmen explodes when the construct is destroyed, projecting superheated steam and shrapnel. Every creature within 5 feet of the construct takes 10 (3d6) fire damage, or half damage with a successful DC 13 Dexterity saving throw.

Longsword. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage. 

Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage.

Net Cannon. Ranged Weapon Attack: +3 to hit, range 5/15 ft., one target, size large or smaller. Hit: the target is restrained. A mechanism within the clockwork watchmen's chest can fire a new with a 20-foot trailing cable anchored within the watchmen's chest. A creature can free itself (or another creature) from the net by using its action to make a successful DC 10 Strength check or by dealing 5 slashing damage to the net at AC 10. The watchmen can fire up to four nets before it must be reloaded.