Cadaver Colossus (5e Creature)
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Gargantuan undead, neutral evil
Saving Throws Dex +6, Wis +5
Immutable Form. The colossus is immune to any spell or effect that would alter its form.
Magic Resistance. The colossus has advantage on saving throws against spells and other magical effects.
Siege Monster. The colossus deals double damage to objects and structures.
Multiattack. The colossus can use its Frightful Presence. It then makes three attacks.
Slam. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 36 (6d8 + 9) bludgeoning damage.
Corpse. Ranged Weapon Attack: +14 to hit, range 60/240 ft., one target. Hit: 27 (4d8 + 9) bludgeoning damage plus 9 (2d8) necrotic damage.
Frightful Presence. Each creature of the colossus's choice that is within 120 feet of the colossus and aware of it must succeed on a DC 16 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the colossus's Frightful Presence for the next 24 hours.
The cadaver colossus is a gruesome creation. It is a gigantic being formed out of hundreds of corpses and over 100 feet tall. To animate such a mass of bodies and give them a human shape, powerful necromancy, alchemy most arcane, and unspeakable blood sacrifice are needed. Once it is brought into unlife, the colossus is under the control of its creator. It is, however, an almost mindless being and while the colossus follows orders, any of its movements will result in destruction and death.
From The Colossus of Ylourgne, Clark Ashton Smith, 1935