Sources
CR
Type
Size
Alignment
Movement

Lightning Hulk

Large Elemental, Chaotic Neutral

Armor Class 15
Hit Points 102 (12d10 + 36)
Speed 0 ft., fly 90 ft. (hover)
STR
18
+4
DEX
21
+5
CON
16
+3
INT
14
+2
WIS
14
+2
CHA
15
+2
Saving Throws DEX +9, CON +7, WIS +6, CHA +6
Skills Perception +6
Damage Resistances cold, thunder; bludgeoning, piercing, slashing, from nonmagical attacks
Damage Immunities lightning, poison
Condition Immunities Exhaustion, Grappled, Paralyzed, Petrified, Poisoned, Prone, Restrained
Senses passive Perception 16
Languages Auran, Giant
Challenge 9 (5,000 XP)

Traits

Illumination. The lightning hulk sheds bright light in a 20-foot radius and dim light for an additional 20 feet.

Lightning Form. The lightning hulk can enter a hostile creature's space and stop there. The first time the lightning hulk enters a creature's space on a turn, or if it begins its turn in a creature's space, that creature takes 7 (2d6) lightning damage. The hulk can also move through a space as narrow as 1 inch without squeezing. A creature that touches the lightning hulk or hits it with a melee attack while within 5 feet of it takes 7 (2d6) lightning damage.

Actions

Arc Lightning. Melee or Ranged Weapon Attack: +9 to hit, reach 10 ft. or range 60 ft., one target. Hit:18 (4d8) lightning damage. If the target is a creature, it can't take reactions until the start of its next turn, and lightning jumps from the target to another creature of the lightning hulk's choice that it can see within 30 feet of the target. The second creature must succeed on a DC 18 Dexterity saving throw or take 18 (4d8) lightning damage.

Lore

At least the lightning hulk and the dust hulk seem satisfied with their lot in life. There's a grace to their existence, as fractured as it seems.