Cactaron (5e Creature)
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Huge plant, neutral good
False Appearance. While the cactaron remains motionless, it is indistinguishable from a normal cactus.
Siege Monster. The cactaron deals double damage to objects and structures.
Spines. At the start of each of its turns, the cactaron deals 5 (1d10) piercing damage to any creature grappling it.
Multiattack. The cactaron makes two slam attacks.
Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 16 (3d6 + 6) piercing damage.
Rock. Ranged Weapon Attack: +10 to hit, range 60/180 ft., one target. Hit: 28 (4d10 + 6) bludgeoning damage.
Animate Cacti (1/Day). The cactaron magically animates one or two cacti it can see within 60 feet of it. These cacti have the same statistics as a cactaron, except they have Intelligence and Charisma scores of 1, they can't speak, and they have only the Slam action option. An animated cactus acts as an ally of the cactaron. The cactus remains animate for 1 day or until it dies; until the cactaron dies or is more than 120 feet from the cactus; or until the cactaron takes a bonus action to turn it back into an inanimate cactus. The cactus then takes root if possible.
What treants are to forests, cactarons are to deserts. Dwelling in ever-changing dunes and amid ancient rock formations, cactarons prefer to hide among inanimate cacti, spending days, months, and years completely still in silent contemplation.
Living Cacti. A cactus that destined to become a cactaron is imbued with ancient magic that builds over years or decades before the process is completed. When it is completed, face-like features develop on the cactus' spiny skin, its arms bend down, and its stem splits into legs. Powerful cactarons can summon desert creatures to aid them or trap enemies in quicksand. Some can even summon elemental beings of fire and air to their sides.
Desert Guardians. Bandits and villains that prefer to lurk in the desert are targeted by cactarons, who gradually congregate, often being seen by their future victims as nothing but a mundane, if unusual, surge of cactus growth. Such unwary creatures are caught completely by surprise when the cacti they thought were mundane spring to life and destroy them and their lairs, leaving nothing behind but bone, blood, and sand.