Ancient Clay Golem

Acid and Necrotic Absorption. Whenever the golem is subjected to acid or necrotic damage, it takes no damage and instead regains a number of hit points equal to the damage dealt.

Berserk. Whenever the golem starts its turn with 65 hit points or fewer, check to see if the golem goes berserk. 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 it can't move to and attack a creature, the golem attacks any nearby object, preferring an object smaller than itself. Once berserk, it remains so until it is destroyed or regains all its hit points.

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 +2 magical.

Multiattack. The ancient golem makes two slam attacks.

Slam. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 20 (2d12 + 7) bludgeoning damage. If the target is alive, it must succeed on a DC 17 Constitution save or have its hit point maximum reduced by an amount equal to the damage taken. If reduced to a hit point maximum of 0, the creature dies. The reduction lasts until removed by the greater restoration spell or other magic.

Haste (Recharge 5-6). Until the end of its next turn, the ancient clay golem magically gains a +2 bonus to its AC, doubles its speed, has advantage on Dexterity saving throws, can use its slam attack as a bonus action, and can use its slam attack as its reaction whenever it gets attacked.

Hasted Slam. Once per round while hasted, the ancient clay golem can use its slam attack against someone within reach as a bonus action.

Hasted Slam. Once per round while hasted, the ancient clay golem can immediately use its slam against someone within reach that is trying to attack it.

The ancient clay golem can perform each of the following mythic actions once per hour, but only one per round.

Ground Stomp. The golem slams its foot on the ground with enormous jarring force, causing 2d6 thunder damage in a 60 foot radius, requiring a Dexterity save DC 17 to all in the area to keep from being knocked prone, and 1d3 damage to any structures in the area.

Necrotic Leech. The golem can restore health by magically sensing and drawing from the injuries of those within 60 feet. For every already injured being in range, the golem regains 10 hit points. This does not cause any additional damage to those injured.

Clapping Crush. If the golem hits the same target with both slam attacks in the same round, it can invoke this mythic action to cause an additional (2d12 + 7) bludgeoning damage as it crushes the victim between both hands.

Punt. The golem kicks at a target, with the same hit chance and initial damage as a normal slam attack. However, on a successful hit, the victim goes flying 1d4 x 10 feet, suffering standard falling damage for the distance traveled and ending up prone. This mythic action can be repeated within the same hour until it succeeds.