Sources
CR
Type
Size
Alignment
Movement

Coldlight Walker

Medium Undead, Chaotic Evil

Armor Class 13 (natural armor)
Hit Points 82 (11d8 + 33)
Speed 30 ft.
STR
15
+2
DEX
10
+0
CON
17
+3
INT
8
-1
WIS
10
+0
CHA
8
-1
Saving Throws INT +2, WIS +3
Damage Immunities cold
Condition Immunities Blinded, Charmed, Exhaustion, Paralyzed, Petrified, Poisoned
Senses darkvision 60 ft., passive Perception 10
Languages
Challenge 5 (1,800 XP)

Traits

Blinding Light. The walker sheds bright light in a 20-foot radius and dim light for an additional 20 feet. As a bonus action, the walker can target one creature in its bright light that it can see and force it to succeed on a DC 14 Constitution saving throw or be blinded until the start of the walker's next turn.

Icy Doom. Any creature killed by the walker freezes for 9 days, during which time it can't be thawed, harmed by fire, animated, or raised from the dead.

Unusual Nature. The walker doesn't require air, food, drink, or sleep.

Actions

Multiattack. The walker makes two attacks.

Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:11 (2d8 + 2) bludgeoning damage plus 14 (4d6) cold damage.

Cold Ray. Ranged Spell Attack: +3 to hit, range 60 ft., one target. Hit:25 (4d10 + 3) cold damage.

Lore

Some humanoids who died from extreme cold but whose spirits languish in the mortal world become coldlight walkers, burning with frigid fury at the meaninglessness of life. Their frostbitten corpses emit a spectral light so intense that mortal eyes can barely stand to look at them. They typically wear the clothing in which they died.