The body of this enormous serpent is covered in mirror-like scales, and a pair of luminous blue eyes gazes from a horned head that ends in an elongated, toothy snout.
Mirror Serpent CR 5
AC 18, touch 12, flat-footed 15 (+3 Dex, +6 natural, –1 size)
hp 57 (6d10+24)
Fort +9, Ref +8, Will +4
Defensive Abilities natural invisibility, reflective skin; DR 5/magic; Resist cold 5, electricity 5; SR 16; Weaknesses vulnerable to sonic
Speed 40 ft., fly 60 ft. (good), swim 40 ft.
Melee bite +12 (1d8+10 plus grab)
Space 10 ft.; Reach 10 ft.
Special Attacks thrash (1d8+10, 20 ft.)
Str 24, Dex 17, Con 18, Int 7, Wis 14, Cha 15
Base Atk +6; CMB +14 (+18 when grappling); CMD 27 (can’t be tripped)
Feats Flyby Attack, Power Attack, Vital Strike
Skills Acrobatics +6, Fly +10, Perception +8, Swim +19
Languages Understands 1 language (can’t speak)
Natural Invisibility (Su)
Reflective Skin (Su)
When a spell (4th level or lower) that targets a mirror serpent fails to penetrate its spell resistance, the mirror serpent can reflect that spell back onto the caster or another creature within 10 feet of the caster as an immediate action. The mirror serpent can’t use this ability when it’s invisible.
A mirror serpent can violently thrash a grappled creature in its mouth before it throws the creature away. When a mirror serpent succeeds at a combat maneuver check to maintain a grapple, the mirror serpent can deal the target damage as normal as well as throw the creature 20 feet in a random direction.
The target must succeed at a DC 16 Reflex saving throw upon hitting the ground or else it takes 2d6 points of falling damage. A target that successfully saves can then attempt an additional DC 15 Acrobatics check to avoid landing prone. The save DC is Dexterity-based.
Environment any coastlines
Mirror serpents are large snakelike beasts that soar as easily through air as they do water. Ages ago, sorcerers employed these serpents to guard their sanctums and vaults. Over the millennia, mirror serpents have grown feral and fiercely territorial.
Because they lack the ability to reproduce and grow their number, mirror serpents are quite rare. The arcane knowledge of their creation rituals hasn’t resurfaced in the current age; if anyone has discovered it, they have kept it a closely guarded secret. Most surviving mirror serpents reside within ruins, staying near the places they were once tasked to guard. Their original purpose as sentinels has imprinted on them a fascination for treasure. Mirror serpents typically live several centuries, unless they suffer a violent fate, but death does not necessarily spell an end to their existence, which is a constant cycle of death and rebirth. Mirror serpents grow much larger and wiser as they age beyond their first century.
A mirror serpent’s body stretches out to a length of 15 feet and weighs 400 pounds.
Unlike most other creatures, mirror serpents don’t permanently die unless their remains are purposefully destroyed to prevent rebirth. Each mirror serpent carries within its body an egg that holds the seed of its next life and matures along with its natural aging.
If a mirror serpent dies prematurely, the egg within it simply decays along with the rest of the creature’s internal organs. When a mirror serpent dies of natural causes, however, its soft tissue is absorbed into the egg as a final act of fertilization, leaving the egg amid the hollow husk of the serpent’s reflective skin. Water is the most ideal location for the egg’s 13-month incubation to take place, and thus when dying, most mirror serpents head for the nearest large body of water. The egg has an exceptionally hard, crystalline shell that protects it from predatory fauna and other dangers while it incubates.
Additionally, shortly after an egg is fertilized, it becomes naturally invisible as a defense mechanism. If the egg remains intact, it eventually hatches, releasing a young mirror serpent into its predecessor’s territory. While the newborn mirror serpent has its own personality, some echoes remain of the previous incarnation, such as intuitions on safe and dangerous areas nearby and an instinctual gravitation toward its old lair.
While mirror serpents resemble snakes in many regards, their snouts are elongated and toothy, like the face of a gharial, and pair of crystalline horns crowns their brows. The reflective sheen of a mirror serpent’s scales can be quite dazzling in bright sunlight as it dives into or leaps out of water, chasing birds and fish with equal prowess. The structure of a mirror serpent’s scales resembles that of actual glazed mirrors, making the creatures vulnerable to sonic attacks. Mirror serpent flesh is hardy and resembles cloudy glass, and they bleed slightly luminescent blue liquid when they’re wounded.
Mirror serpents’ primary diet consists of amphibian and avian animals that live in or near their territories, though they are typically not opposed to eating those humanoids foolish enough to blunder into their domains, especially if the mirror serpent guards treasure of particular power, secrecy, or value. These serpents rarely fight to the death unless they feel there’s no other choice. One function of their hunting is to keep major predators away from their territory so that when the mirror serpent dies, its egg has a better chance of surviving its incubation period. Mirror serpents use their natural invisibility when investigating whether creatures are food or a threat. When they choose to fight, mirror serpents make sudden attacks and retreats, turning invisible in order to hide their movements and strike from a new vantage point. They use their savage bites to separate their foes and attempt to fling them into water, where the serpents can take advantage of their superior mobility.
Habitat and Society
Most mirror serpents lair near or within ancient ruins so they can seek out and collect treasures and trinkets that lie forgotten among the devastation.
Each lair is usually located near a body of water, and its opening is most likely overlooking or hiding below the water’s surface. A common place for a den is on the side of a natural cliff or a part of a ruined tower that has no other access points. Even when the entrance is below the surface, the actual living area is situated above water level. When in their lairs, mirror serpents lie curled in the center, while their treasure is spread against the surrounding walls. Not all of the treasure—or even most of it—is of actual monetary value, since items need only to gleam and be beautiful to catch the attention of the serpents. Mirrored scales, or even a complete husk, are often found among the piled treasure as the newest incarnation has dragged the glittering remains of the previous mirror serpent into the lair.
Mirror serpents hate creatures that defile nature or deface structures within their domain, causing them to become violent from the outset. It’s possible to communicate with mirror serpents by speaking an ancient or forgotten language; the knowledge of that language was imbued in the creatures during the ritual of their creation and remains with them through each rebirth. Once a person has entered the territory of a mirror serpent, there’s a small window of opportunity to speak up in order to keep it from attacking and driving the intruder away.
An offering of treasure or ornate trinkets goes a long way toward appeasing a mirror serpent to allow swift safe passage through its domain. If the territories of two mirror serpents are adjacent to each other, minor clashes may arise between the two beasts. Such fights rarely lead to death, as one them eventually yields to the more powerful rival, accepting defeat over endangering even its greatest enemy’s cycle of rebirth.
Mirror serpent scales are a valued material for those who craft magical armor. With proper techniques, it’s possible to forge a suit of scale mail that retains a portion of the spell-reflecting ability that mirror serpents have. If a person comes upon a mirror serpent egg, she can attempt to train the newly hatched serpent and turn it into a guardian or a companion. However, the echoes of lifetimes it has spent free in the wild make this a challenge.
Pathfinder Adventure Path #125: Tower of the Drowned Dead © 2017, Paizo Inc.; Authors: Ron Lundeen, with Nathan King, Isabelle Lee, Erik Mona, Kalervo Oikarinen, and David Schwartz.