Sources
CR
Type
Size
Alignment
Movement

Kakkuu Spyder-Fiend

Medium Fiend (demon), Chaotic Evil

Armor Class 15 (natural armor)
Hit Points 91 (14d8 + 28)
Speed 30 ft., climb 30 ft.
STR
17
+3
DEX
15
+2
CON
14
+2
INT
6
-2
WIS
10
+0
CHA
10
+0
Saving Throws DEX +5, CON +5, WIS +3
Skills Perception +3, Stealth +5
Damage Resistances cold, fire, lightning
Damage Immunities poison
Condition Immunities Poisoned
Senses darkvision 60 ft., passive Perception 13
Languages understands Abyssal but can't speak
Challenge 5 (1,800 XP)

Traits

Magic Resistance. The kakkuu has advantage on saving throws against spells and other magical effects.

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

Web Sense. When in contact with a web, the kakkuu knows the exact location of any other creature in contact with the same web.

Web Walker. The kakkuu ignores movement restrictions caused by webbing.

Actions

Multiattack. The kakkuu makes a Web Snare attack, uses Reel, and makes a Bite attack.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:14 (2d10 + 3) piercing damage plus 10 (3d6) poison damage.

Reel. The kakkuu pulls each creature within 60 feet of itself that is grappled by its Web Snare up to 30 feet straight toward itself.

Web Snare. Ranged Weapon Attack: +6 to hit, reach 30/60 ft., one Large or smaller creature. Hit:The target has the grappled condition (escape DC 13). While grappled, the target also has the restrained condition. A web snare grappling a creature can be attacked and destroyed (AC 10; 10 hit points; immunity to bludgeoning, poison, and psychic damage).

Lore

Resembling enormous spiders, kakkuus are the most numerous and least intelligent spyder-fiends. In large conflicts, they serve as foot soldiers, but they prefer to avoid more powerful Fiends, who boss them around. Left on their own, kakkuus lurk in ambush and use their webs to snare prey.