This enormous worm is covered with dark purple plates of chitinous armor. Its giant, tooth-filled mouth is the size of an ox.
Speed 20 ft., burrow 20 ft., swim 10 ft.
Str 35, Dex 6, Con 25, Int 1, Wis 8, Cha 8
Environment any underground
Purple worms are giant scavengers that inhabit the deepest regions of the world, consuming any organic material that they encounter. They are notorious for swallowing their prey whole. It is not uncommon to hear of a group of adventurers vanishing down the ravenous maw of a purple worm, screaming as they disappear one by one.
Although they seek to consume living creatures, purple worms also consume vast amounts of dirt and minerals as they burrow underground. The insides of a purple worm may contain a considerable number of gemstones and other items able to withstand the corrosive acid inside its gullet. In areas filled with valuable minerals, such as those near dwarven mines, the natural tunnels created by burrowing purple worms are often filled with vast amounts of unrefined ores.
A purple worm usually claims a large underground cavern as its den, and while it returns here to rest and digest food, it spends the majority of its time on the prowl, burrowing through the endless dark or slithering along established tunnels in the constant drive to feed its immense hunger. Although not completely mindless, purple worms are rather stupid. They make popular guardians for those who have the magic to control them or a chamber in their lair large enough to hold one captive.
The standard purple worm encountered by cave-delving adventurers is not the only such species in the larger family of gigantic burrowing worms.
Similar in many respects to the purple worm save for its brown and gray coloration, the mottled worm is an aquatic relative of the purple worm that dwells in salt or fresh water. Rather than conserve oxygen within their coelums as their violet cousins do, mottled worms are actually able to draw water into their coelums, where oxygen diffuses into their surrounding bloodstream via specialized gill-like organs. As a result, like fish, mottled worms can stay submerged indefinitely if the surrounding water is properly oxygenated. Since their coelums have enough stored fluid to allow their internal gills to function, mottled worms are also able to survive out of water for several hours, though the uncomfortable drying process makes them inclined to return to the water after about an hour on land.
Mottled worms cannot burrow through stone like their cousins, but are adept at moving through the muck and sand found on the seafloor and on tidal shelves (burrow speed 20 feet in mud, sand, or silt). Varieties exist that lurk both in shallow waters, preying on aquatic species, birds, and land animals, and in the deepest reaches of the sea where they build gigantic upright tubular formations created from their bodily waste. Such deep sea specimens are highly resistant to extremes in both temperature and pressure and, as a result, are often found near volcanic vents.
Unlike purple worms, which are solitary, mottled worms of this deep-dwelling variety typically live in colonies of three to 12 individuals, and even the mighty krakens think twice before invading their hunting grounds.
Mottled worms have a poisonous bite rather than a poisonous sting.
Less common than purple worms or even their mottled worm cousins, these are found only in the most desolate regions. Thought by many to be mere legend, the great worms have been exposed to great magic, such by slowly digesting artifacts embedded in their gullets, consuming the foci of ley lines, interacting with magical portals, swallowing mighty demons, and so on. The worms gain powers appropriate to this magic and sometimes grow to unusual sizes, or gain near-human intelligence or stranger abilities; most also have extended lifespans, with some speculated to be over 1,500 years old. Those that grow in size have even greater appetites than their fellows, and their territory quickly becomes depleted of resources, turning into a wasteland as the creatures spiral outward in search of more to consume. Others hibernate for long periods before rising, famished and hunting anything they can find. These long periods of inactivity—sometimes spanning decades at a time or longer—have contributed to the near-legendary status of these worms.
A great worm has one or more of the following abilities, usually related to the source of its mutation. For every three of these abilities it has, increase its CR by +1.
A great worm naturally exudes energy (usually the same type as its immunity or resistance, if any). Every 1d4 rounds, this energy builds up enough to deal 4d6 hit points damage to the first creature it hits that round with one of its natural attacks. Creatures it swallows take 1d6 energy damage per round in addition to other damage from the gullet. If the great worm burrows, the walls of the burrow-tunnel are charged with this energy, dealing 1d6 hit points of damage per round of contact for 4 rounds after the great worm passes. Alternatively, instead of a touch attack, the great worm may gain a breath weapon usable every 1d4 rounds (30-ft. cone, 8d6 damage, Reflex half DC 25); the save DC is Constitution-based.
A great worm heals when exposed to energy to which it has immunity. Any energy attack of this type used against the worm heals 1 point of damage for every 3 points of damage it would otherwise deal. It cannot heal above its normal hit points in this way. The worm gets no saving throw against magical attacks that deal this kind of damage.
A great worm has energy resistance 20 to two kinds of energy or immunity to one kind of energy. Sometimes it may gain a weakness appropriate to the source of its power or the opposite of its element; a cold-resistant great worm might become vulnerable to fire, a fire worm might take damage from cold or exposure to water, and so on.
A great worm has fast healing 10. This ability cannot repair acid or fire damage. If the great worm is immune to fire or acid, it cannot repair damage from an energy source to which it is not immune.
A great worm’s tremorsense expands to 120 feet or even 360 feet.
Suffused with the power of an elemental plane, an undead force, or some connection to the Negative Energy Plane, a great worm has a 25% chance to ignore extra damage from a critical hit, sneak attack, poison, paralysis, or stunning.
Although the deep-dwelling purple worm is the most common of its ilk, variant immense worms of differing colors dwell in other remote wildernesses.
Aquatic Worm: A sleek, mottled blue-and-green variant of the giant worm dwells in deep underground lakes or tropical seas (this variant loses its burrow speed but increases its swim speed to 40 feet).
Crimson Worm: A deep crimson variant of even greater size dwells in remote badlands and rocky deserts (this variant is never less than Colossal in size). Other species doubtless remain to be discovered in the far corners of the world.
Pathfinder Chronicles: Dungeon Denizens Revisited. Copyright 2009, Paizo Publishing, LLC; Authors: Clinton Boomer, Jason Bulmahn, Joshua J. Frost, Nicolas Logue, Robert McCreary, Jason Nelson, Richard Pett, Sean K Reynolds, James L. Sutter, and Greg A. Vaughan.