Citadel Spider

Gargantuan monstrosity, typically neutral evil

Armor Class

18 (natural armor)

Hit Points

310 (20d20 + 150)

Speed

50 ft., climb 50 ft.

Condition Immunities

charmed, exhaustion, frightened

Senses

blindsight 30 ft., darkvision 120 ft.

Challenge

18

Proficiency Bonus

+6

Legendary Resistance (3/Day)

If the spider fails a saving throw, it can choose to succeed instead.

Spider Climb

The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Web Walker

The spider ignores movement restrictions caused by webbing.

Actions

Multiattack

The spider makes two Bite attacks. It can replace one of these attacks with a use of Web Bomb.

Bite

Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 7 (2d6) poison damage.

Web Bomb

Ranged Weapon Attack: +14 to hit, range 300 ft./600 ft., one target. Hit: 24 (3d10 + 8) bludgeoning damage, and the target and all creatures within 10 feet of it must succeed on a DC 19 Dexterity saving throw or take 10 (3d6) acid damage and have the restrained condition until the start of the spider's next turn.