Prism Spider

Small monstrosity, unaligned

Armor Class 14 (natural armor)
Hit Points 71 (11d6 + 33)
Speed 30 ft., climb 30 ft.

STR	DEX	CON	INT	WIS	CHA
19 (+4)	16 (+3)	16 (+3)	2 (-4)	13 (+1)	6 (-2)

Skills Perception +9, Stealth +11, Survival +9
Damage Immunities varies
Condition Immunities varies
Senses blindsight 10 ft., darkvision 60 ft., passive Perception 19
Challenge 9 (5,000 XP)

Special Traits

• • Shifting Power. As the prism spider shifts color, its immunities and attacks change. Roll a d6 at the start of the spider’s turn and consult the table below. Use the result in place of one of the spider’s attacks.

d6	Color/Immunity	Other
1	Green/Acid	Spit Acid. The spider spits a 30-foot line of acid that is 5 feet wide. Each creature in the line must make a DC 16 Dexterity saving throw, taking 31 (9d6) acid damage on a failed save, or half as much damage on a successful one.
2	Orange/Fire	Inferno Shield. The spider is wreathed in intense, thick flames, shedding bright light in a 20-foot radius and dim light for an additional 20 feet. Whenever a creature within 5 feet of the spider hits it with a melee attack before the end of the prism spider’s next turn, the shield erupts, dealing 27 (6d8) fire damage to the creature.
3	Grey/Disease	Fetid Bite. When the prism spider makes a bite attack, the target must succeed on a DC 17 Constitution saving throw against disease or become poisoned until the disease is cured. Every 24 hours that elapse, the target must repeat the saving throw, reducing its hit point maximum by 16 (3d10) on a failure. The disease is cured on a success. The target dies if the disease reduces its hit point maximum to 0. This reduction to the target’s hit point maximum lasts until the disease is cured.
4	Blue/Lightning	Shocking Aura. Until the end of the spider’s next turn, creatures who enter or begin their turns within 15 feet of the prism spider must make a DC 16 Dexterity saving throw, taking 27 (6d8) lightning damage on a failed saving throw, or half as much damage on a successful one. Creatures wearing metal armor have disadvantage on this saving throw.
5	White/Cold	Hoarfrost. Until the beginning of the spider’s next turn, creatures who enter or begin their turns within 15 feet of the prism spider must make a DC 16 Constitution saving throw. On a failed saving throw, the target takes 28 (8d6) cold damage. A creature who takes cold damage from this effect has their movement speed halved, cannot take reactions, and can only take one action or one bonus action on their turn. They can only make one melee or ranged attack on their turn, regardless of other class features or magic items.
6	Purple/-	Heal. The spider magically heals itself for 36 (8d8) damage, and it has advantage on saving throws against spells and other magical effects until the end of its next turn.

• Spider Climb. The prism spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
• Web Sense. While in contact with a web, the spider knows the exact location of any other creature in contact with the same web.
• Web Walker. The spider ignores movement restrictions caused by webbing.

Actions

• Multiattack. The spider uses one of its shifting power abilities and makes a bite attack.
• Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 13 (2d8 + 4) piercing damage.
• Web (Recharge 5-6). Ranged Weapon Attack: +7 to hit, range 30/60 ft., one creature. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 14 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 10; hp 10; the same resistances that the prism spider is benefiting from at that time; immunity to bludgeoning, poison, and psychic damage).

About

Alarmed and posturing aggressively, the great spider changes from a mottled brown to a shifting array of colorful patterns pulsing across its surface as it attacks.

Prism spiders are exceedingly rare giant spiders of mysterious origin.

Like most spiders, they are predatory, and though most are reclusive hunters of wild game, some have learned to see humanoids as a food source. When this happens, it is often sadly the case that these beautiful animals must be put down. Sadder still, despite their rarity, prism spiders are sometimes poached for their carapaces. In death, a prism spider’s carapace retains the color and immunity it had in the moment it died, and the carapace of a prism spider who died fighting may be crafted into a set of full plate, offering the wearer resistance to whatever immunity the carapace holds. Carapaces sell for 1,000 gp, and finished prism spider armor for twice as much. (It is otherwise identical to regular full plate, but able to be additionally enchanted at regular price, if desired.)

A prism spider is hardly helpless prey for the harvesting. With its bite and spined legs alone, prism spiders are formidable foes. Add to that their prismatic powers and few would-be poachers escape with their lives. Failed poaching, however, can be what leads a prism spider to see humanoids as food, and thus need to be dealt with for the safety of surrounding communities.

When calm, a prism spider is a mottled black and brown in color and looks like an ordinary giant spider. Once the spider is alarmed or aggressive, however, it begins to change colors in brilliant and beautiful patterns, some speckled, striped, diamond-patterned, or even swirled. No one knows if the prism spider changes color deliberately, due to some incomprehensible spider logic, or whether the changes are merely random.