Starry Golem

A supporting “mook” for a boss fight for my converted darkness gathering adventure (this is a mook because it’s not really a challenge for 8 x level 16 PCs, just a roadblock). This golem was in the original.  Though it was a standard golem in the adventure its description was quite original and inspired this modified version. 

Large construct (mythic), unaligned
Armour Class 19 (Natural Armor)
Hit Points 256 (17d10 + 85)
Speed 30 ft.

22 (+6) 9 (-1) 20 (+5) 3 (-4) 11 (+0) 1 (-5)

Damage Immunities Poison, Psychic; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks that aren’t Adamantine
Condition Immunities Charmed, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned
Senses Darkvision120 ft., Passive Perception 10
Languages Understands the languages of its creator but can’t speak
Challenge 10 (5,900 XP)

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

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

Modified Immutable Form. The golem is immune to any spell or effect that would alter its form. However, the starry golem is fully healed if a by a mud to rockspell, it slowed by a rock to mudspell and a flesh to stonespell has a reverse effect removing its damage immunities for the duration.

Starry Enchantment. The bits of glass embedded in the golem provides an enchantment that maximizes its hit points and increases its AC by +2.

Multiattack. The golem makes two slam attacks.

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

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.

Statues of black onyx stand at the east and west limits of the crossway. These statues are, in fact, stone golems set to guard the tower against intrusion. The black forms, carved to resemble gibbering madmen, are studded with small bits of cut glass. When the glass catches the light, the effect resembles a starry night sky (the glass bits also hold enchantments that serve to lower the golems’ base AC and increase their hit points; these enchantments are not transferable). Whenever unauthorized visitors appear within the crossway, the golems follow their instructions to destroy all intruders. The stone golems pursue intruders to any and all parts of the tower, but they never leave the confines of the building