Multiattack

The golem makes three Slam attacks.

Slam

_Melee Weapon Attack:_ +9 to hit, reach 5 ft., one target. _Hit:_ 21 (3d10+5) bludgeoning, piercing, or slashing damage, as determined by Mold Hand. The target must succeed on a DC 16 STR save or suffer an effect based on the type of damage: knocked prone (bludgeoning), pushed up to 10 feet away from the golem (piercing), or its speed is reduced by 10 feet until the end of its next turn (slashing).

Haste (Recharge 5-6)

Until the end of its next turn, the golem magically gains a +2 bonus to its AC, has advantage on DEX saves, and can make a Slam attack as a bonus action.