◆ World Build
◆
Image promptlarge aberrant shadow panther, sleek elongated body of depthless blue-black light-swallowing fur, six faint glinting eyes, inky vapor trailing from paws, recoiling and shrinking from a bright lantern's beam, thinning where light falls, lightless underground ruin, broken pillars, dripping stone, a single fallen lantern casting a hard cone of light into blackness, tense snarling pose at the light's edge, black and cold palette, dark fantasy, grimdark, painterly digital art, dramatic chiaroscuro lighting, muted desaturated palette with corrupted-crimson accents, weathered post-Cataclysm atmosphere, intricate high detail, cinematic composition

Gloom Panther

Large Aberration, Chaotic Evil
CR 7LurkerDungeon / Structure
AC 16
HP 105 (14d10 + 28)
Speed 50 ft., Climb 30 ft.
STR
17
+3
save +3
DEX
20
+5
save +8
CON
15
+2
save +2
INT
7
−2
save −2
WIS
16
+3
save +6
CHA
11
+0
save +0
Skills Perception +6, Stealth +11
Resistances Cold, Necrotic
Immunities Charmed, Frightened
Senses Darkvision 120 ft.; Passive Perception 16
Languages —

Traits

Shadow Blend. While in Dim Light or Darkness, the Gloom Panther can take the Hide action as a Bonus Action and needs no cover to hide.

Light Aversion. While in Bright Light, the Gloom Panther's attacks have Disadvantage and it can't use Shadow Step.

Shadow Killer. The Gloom Panther's first attack made from the Hidden condition deals an extra 18 (4d8) Necrotic damage.

Actions

Multiattack. Makes one Bite and two Claw attacks.

Bite. Melee Attack Roll: +8, reach 5 ft. Hit: 14 (2d8 + 5) Piercing damage.

Claw. Melee Attack Roll: +8, reach 5 ft. Hit: 10 (1d10 + 5) Slashing damage.

Devouring Dark (Recharge 6). The shadows around the Gloom Panther come alive. Every enemy in a 20-foot Emanation makes a DC 16 Dexterity save.

  • Failure: 27 (6d8) Necrotic damage, and the target's Hit Point maximum is reduced by the same amount (restored by a Long Rest).
  • Success: Half damage, HP maximum not reduced.

Bonus Actions

Shadow Step. The Gloom Panther teleports to a point within 60 feet that is in Dim Light or Darkness. The destination point must also be in Dim Light or Darkness. After teleporting, it can take the Hide action.

How to Use

The Gloom Panther can't be pinned down. This is the hardest of the three Lurkers — because it teleports.

Loop:

  1. It emerges from the darkness: Bite (14 + 18 = 32) + Claw (10) + Claw (10) = 52 damage.
  2. Shadow Step (Bonus Action) → teleports 60 feet away, into another shadow.
  3. Shadow Blend → instantly hides there (no cover needed!).
  4. The party searches for it. Can't find it. Next turn, another 52 damage.

This is the perfect example of "hit-and-run." The party can never confront it.

But the solution is very clear: LIGHT.

Light Aversion: In Bright Light, its attacks have Disadvantage and Shadow Step doesn't work.

A single Daylight spell, or enough torches, turns the Gloom Panther into an ordinary creature. It can't teleport, can't hide, can't flee.

This is a deliberate "lock-and-key" design. The party has to find the right tool. Once they do, the encounter flips completely — and it feels earned.

DM note: Give the party a hint. In a cave the Gloom Panther hunts in, have burned-out torches and broken lanterns. Make it clear that someone tried this and it worked.