Flesh Golem

Aversion of Fire. If the golem takes fire damage, it loses its immunity to the frightened condition and has disadvantage on attack rolls and ability checks until the end of its next turn.

Berserk (55 HP or Fewer). When the golem starts its turn, roll a d6. On a 6, the golem goes berserk. On each of its turns while berserk, the golem attacks the nearest creature it can see. If no creature is near enough to move to and attack, the golem attacks an object, with preference for an object smaller than itself. Once the golem goes berserk, it continues to do so until it is destroyed or regains all its HP. The golem's creator, if within 60 feet of the berserk golem, can try to calm it by speaking firmly and persuasively. The golem must be able to hear its creator, who must take an action to make a DC 15 CHA (Persuasion) check. If the check succeeds, the golem ceases being berserk. If the golem takes damage while still at 55 HP or fewer, the golem might go berserk again.

Construct Nature. The golem doesn't require air, food, drink, or sleep.

Flesh Golem Resilience. The golem is immune to poison damage and to bludgeoning, piercing, and slashing damage from nonmagical attacks. In addition, it is immune to exhaustion and to the charmed, frightened, paralyzed, petrified, and poisoned conditions.

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

Lightning Absorption. Whenever the golem is subjected to lightning damage, it takes no damage and instead regains HP equal to the lightning damage dealt.

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

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