Blooming Golem

Elemental Blooms. The Blooming Golem is covered in an assortment of magical flowers, fungi, and lichens. The golem can trigger a variety of effects upon taking elemental damage. Whenever an effect triggers, it lasts for the duration specified, ending early if another Elemental Blooms effect triggers. Once triggered, an Elemental Blooms effect does not function until the end of the golem's next turn.

Thresher Thorns. These bright blue flowers from the frigid north grow upon the shoulders of the golem, but conceal vicious living briars. The first time the golem would take cold damage, it instead takes no damage and the Thresher Thorns sprout in two long clusters. These wildly waving tendrils lash out wildly, attacking any creature that leaves or enters their reach until the end of the golem's next turn.

Cinder Blooms. These beautiful, small, red flowers cover the golem in a lovely pattern. The first time the golem would take fire damage, it instead takes no damage as the flowers eject a cloud of pollen, which ignites in a fiery explosion. All creatures within 15 ft. of the golem (excluding Maribelle) take 10 (2d10) fire damage.

Ferran Lichen. A thin layer of this vivid green lichen coats the stone skin of the golem. The first time the golem would take fire damage, it instead takes no damage as the lichen begins to emit corrosive fumes. Until the end of the golem's next turn, any time a creature within 5 ft. of the golem hits it with a melee attack, that creature takes 2d8 acid damage.

Devil's Caps. These ominous black mushrooms bloom from the legs and arms of the golem. The first time the golem would take necrotic damage, it instead takes no damage as the mushrooms begin to glow with a disturbing black aura. Until the end of the golem's next turn, any creature that ends its turn within 15 ft. of the golem takes 1d10 necrotic damage. The golem's slam attacks also deal an additional 1d10 necrotic damage on a hit as long as this effect persists.

Kelpie Lure. This long, blueish vine coils around the torso of the golem. The first time the golem would take lightning damage, it instead takes none as the vine animates, crackling with electricity. This vine can then attack, replacing one of the golem's pod or slam attacks (including as a Legendary Action).

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.

Regeneration. The golem regains 10 hitpoints at the start of each of its turns.

Multiattack. The golem makes two slam attacks. It can replace one of these slam attacks with a pod.

Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 5) bludgeoning damage. If the target is a creature, it must succeed on a DC 16 Strength saving throw or be knocked prone.

Thresher Thorns (Elemental Bloom). Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 6 (2d6) slashing damage and 3 (1d6) cold damage. If the target is a creature, it must succeed on a DC 16 Constitution saving throw or have its movement speed reduced by half until the end of the golem's next turn.

Kelpie Lure (Elemental Bloom). Melee Weapon Attack: +9 to hit, reach 15 ft., one target. Hit: 6 (1d12) piercing damage and 6 (2d6) lightning damage. If the target is a creature, it must succeed on a DC 16 Constitution saving throw or be stunned until the end of its next turn.

Red Pod (Recharge 3-6). The golem launches a large red pod at a point it can see within 60 ft. All creatures within 20 ft. of that point must make a DC 16 Dexterity saving throw or take 12 (4d6) fire damage and be blinded until the end of their next turn. On a successful save a target takes half damage and is not blinded.

Green Pod (Recharge 3-6). The golem launches a large red pod at a point it can see within 60 ft. All creatures within 20 ft. of that point must make a DC 16 Constitution saving throw or take 12 (4d6) poison damage and be poisoned for one minute. While poisoned this way, affected creatures take 2d6 poison damage at the start of each of their turns. An affected creature can repeat the saving throw at the end of each turn, ending it on a success. On a successful save a target takes half damage and is not poisoned.

Yellow Pods (Recharge 5-6). The golem launches a series of yellow pods at up to four targets it can see within 60 ft. Targets chosen must make a  DC 16 Wisdom saving throw or be paralyzed for one minute. An affected creature can repeat the saving throw at the end of each turn, ending it on a success. If the affected creature(s) take damage, the damage is critical damage, but ends this effect instantly.