Obsidian Spider

Large construct, unaligned

Armor Class 17 (natural armor)
Hit Points 85 (10d10 + 30)
Speed 40 ft.

STR	DEX	CON	INT	WIS	CHA
20 (+5)	10 (+0)	16 (+3)	1 (-5)	10 (+0)	1 (-5)

Damage Immunities poison, psychic; bludgeoning, piercing, and slashing from nonmagical attacks that aren’t adamantine
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 120 ft., truesight 30 ft., passive Perception 10
Languages understands Undercommon but can’t speak
Challenge 6 (2,300 XP)
Proficiency Bonus +3

SPECIAL TRAITS

• Immutable Form. The spider is immune to any spell or effect that would alter its form.
• Magic Resistance. The spider has advantage on saving throws against spells and other magical effects.
• Magic Weapons. The spider’s weapon attacks are magical.

ACTIONS

• Multiattack. The spider makes a Bite attack and uses Skittering Charge or Interweave Fates.
• Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 10 (1d10 + 5) piercing damage, and the target must make a DC 14 Constitution saving throw, taking 18 (4d8) poison damage on a failed save, or half as much damage on a successful one.
• Skittering Charge. The spider moves up to 40 feet in a straight line and can move through the spaces of Medium or smaller creatures. The first time it enters a creature’s space during this move, the creature must make a DC 14 Dexterity saving throw or take 14 (2d8 + 5) piercing damage.
• Interweave Fates (1/Day). The spider shoots a strand of magical webbing that jumps between up to 5 creatures that are within 30 feet of the spider and each other. Each creature must make a DC 14 Dexterity saving throw. On a failure, a creature is connected to each other creature that failed its saving throw. Connected creatures are tethered together by the webbing and can’t move further away from each other than they currently are. Additionally, whenever one of the tethered creatures takes damage that isn’t psychic, each other connected creature must make a DC 14 Constitution saving throw or take the same amount of psychic damage. A strand of magical webbing connecting two creatures can be broken as an action with a DC 14 Strength (Athletics) check. The webbing can also be attacked and destroyed (AC 12; hp 10; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).