Multiattack

The golem makes two slam attacks and one catapult attack.

Slam

Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 22 (4d6 + 8) bludgeoning damage.

Catapult

The war machine golem hurls a boulder at a point it can see within 120 feet of it. Each creature within 10 feet of that point must make a DC 19 Dexterity saving throw. On a failure, a target takes 16 (3d10) bludgeoning damage and is knocked prone. On a success, a target takes half the damage and isn't knocked prone.

Fire Breath (Recharge 5-6)

The war machine golem breathes fire in a 60-foot cone. Each creature in the area must make a DC 19 Dexterity saving throw, taking 35 (10d6) fire damage on a failed save, or half as much damage on a successful one.