Century Worm | New Monster for Fifth Edition

Some believe that nature is a chaotic, destructive force that cares little for the concepts of morality or fair play. Such devotees of wild destruction and entropy often point to the dreaded century worm as evidence of their philosophy and single out the repulsive, voracious creature as the living embodiment of the uncaring wrath of the natural world.

A century worm is composed of seven translucent segments of pulpy flesh topped by a menacing head partially covered by a hood of rough, dark brown skin. Its round, tooth-lined mouth easily accommodates an ogre. Hundreds of squirming larvae about the size of a human’s arm line the worm’s stomach, which doubles as a womb. These little creatures sometimes spill out of the worm’s mouth, though they die within an hour for want of their parent’s life-giving nutrient bile.

Century worm larvae are far from harmless to creatures that find themselves trapped within the parent. Once the little one has sapped the life out of a victim, one larva takes up residence in the victim’s body, where it gestates for a period of 100 years.

Century Worm

Gargantuan monstrosity, unaligned

Armor Class 19 (natural armor)

Hit Points 462 (28d20 + 168)

Speed 30 ft., burrow 20 ft.

Abilities Str 30 (+10), Dex 7 (-2), Con 22 (+6), Int 1 (-5), Wis 11 (+0), Cha 4 (-3)

Saving Throws Con +12, Wis +6

Damage Resistances acid

Senses blindsight 30 ft., tremorsense 120 ft.


Challenge 19 (22,000 XP)



Multiattack. The worm uses its bite. It then makes one larva bite attack against each creature it has swallowed.

Bite. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 37 (6d8 + 10) piercing damage. If the target is a Large or smaller creature, it must succeed on a DC 20 Dexterity saving throw or be swallowed by the worm. A swallowed creature is blinded and restrained, it has total cover against attacks and other effects outside the worm, and it takes 28 (8d6) acid damage at the start of each of the worm’s turns.

If the worm takes 40 damage or more on a single turn from a creature inside it, the worm must succeed on a DC 22 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the worm. If the worm dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 20 feet of movement, exiting prone.

Larvae Bites. Melee Weapon Attack: +12 to hit, reach 5 ft., one target in the worm’s stomach. Hit: 36 (8d8) piercing damage and the target must succeed on a DC 20 Constitution saving throw. On a failed saving throw, one of the larvae burrows through the creature’s skin and makes its way towards the victim’s heart; the target contracts century worm disease. While diseased, the victim must make another DC 20 Constitution saving throw at the end of each of its turns. On a successful saving throw, nothing happens. On a failed saving throw, the worm reaches the target’s heart and the target dies. The worm then latches onto the corpse’s spine and begins to grow into a new century worm. If the disease is cured before the century worm larva kills its host, the unborn century worm is disintegrated.

Keening (Recharge 5-6). The worm emits a terrible keening sound. Each creature within 60 feet of the worm must make a DC 20 Constitution saving throw. On a failed saving throw, a creature takes 22 (4d10) thunder damage and is permanently deafened. On a successful saving throw, a creature takes half as much damage and is deafened until the end of its next turn.


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Art by Jason Rhineville.

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