Amalgam

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

Radiant Absorption. Whenever the golem is subjected to radiant damage, it takes no damage and instead regains a number of hit points equal to the radiant damage dealt.

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

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

Multiattack. The golem makes two slam attacks and one swat attack.

Slam. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 18 (3d8 + 6) bludgeoning damage.

Swat. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 22 (4d8 + 6) bludgeoning damage. When hit, target must make a Strength save with a DC=damage done on the hit. On failure, they are moved back 20 feet and knocked prone.

Wail: The wail of the Amalgam can grate on the nerves of those who hear it. At the start of each round, anyone who can hear the Amalgam must make a Wisdom saving throw, DC 13. Those who fail, if they are susceptible to fear, make all attacks against the Amalgam at disadvantage.

Grapple: If a creature moves out of the range of the golem, it can attempt to grapple with a +11 modifier. Once grappled, the golem uses the creature as a weapon for its slam attack. This works like a regular slam, but both the target and the weapon take the damage. The weapon takes damage even on a miss. Breaking free of this grapple requires a DC 16 strength save.