Ice Golem

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

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.

ACTIONS
Slam. Melee Weapon Attack: +4 to hit, reach 5ft., one target. Hit: 17 (2d8+3) bludgeoning damage.

Icy Breath (Recharge 6). The golem exhales a chilling fog a 15-foot cone. Each creature in that area must make a DC 13 Constitution saving throw, taking 8 (2d6) cold damage on a failed save, or half as much damage on a successful one.