Brick golem up the tower

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

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

Magic Weapons. The golem's weapon attacks are magical.

Multiattack. The golem makes two slam attacks or one slam attack and one hammer attack.

Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 19 (3d8 + 6) bludgeoning damage.

Hammer. Area effect: Choose a 20 square ft (2x2) area which you can see the center of it within 15 feet. You swing your arm up and it transforms into a huge hammer slamming into the center of this area. Each creature huge or smaller in the area must succeed a DEX Saving Throw 15 or loose 2d8+5 bludgeoning damage and be knocked prone.

Slow (Recharge 5–6). The golem targets one or more creatures it can see within 10 feet of it. Each target must make a DC 17 Wisdom saving throw against this magic. On a failed save, a target can't use reactions, its speed is halved, and it can't make more than one attack on its turn. In addition, the target can take either an action or a bonus action on its turn, not both. These effects last for 1 minute. A target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.