Killer Rabbit of Caerbannog
A Beast Most Foul
At first glance, it appears to be a harmless white rabbit — soft-furred, bright-eyed, almost serene. Yet those who linger too long before its cave seldom leave with all their limbs attached.
The Killer Rabbit of Caerbannog is no natural creature. Whether born of curse, divine jest, or abyssal mockery, it possesses preternatural speed and a hunger for violence wholly disproportionate to its size.
Its cave is marked by unnaturally clean bones, stripped of flesh with surgical precision. The grass outside grows lush and green, as if nourished by blood unseen.
Small monstrosity, chaotic evil
Armor Class: 17 (supernatural agility)
Hit Points: 136 (16d6 + 80)
Speed: 40 ft., jump 30 ft. (standing long jump), 20 ft. vertical leap
STR 14 (+2), DEX 22 (+6), CON 20 (+5)
INT 6 (–2), WIS 14 (+2), CHA 8 (-1)
Saving Throws Dex +10, Con +9
Skills Perception +6, Stealth +10
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities frightened
Senses darkvision 60 ft., passive Perception 16
Languages –
Challenge 8 (3,900 XP)
Proficiency Bonus +8
Traits
Preternatural Velocity. The rabbit does not provoke opportunity attacks.
Blood-Flecked Fury. When the rabbit reduces a creature to 0 hit points, it can immediately move up to its speed and make one Bite attack as a bonus action.
Unassuming Horror. A creature that starts its turn within 30 feet of the rabbit and can see it must succeed on a DC 15 Wisdom saving throw or be frightened until the end of its turn as it comprehends the wrongness of the beast.
Creatures that fail by 5 or more are stunned until the end of their turn.
Vorpal Incisors. On a critical hit with its Bite, the target must succeed on a DC 16 Constitution saving throw or be decapitated. Creatures immune to slashing damage are immune to this effect.
Actions
Multiattack. The rabbit makes two Bite attacks.
Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 18 (3d8 + 6) piercing damage plus 7 (2d6) slashing damage.
If both Bite attacks hit the same creature in a turn, the target must make a DC 16 Strength saving throw or be knocked prone and grappled (escape DC 16).
Bounding Lunge (Recharge 4–6). The rabbit leaps up to 30 feet to a space adjacent to a creature and makes a Bite attack with advantage.
On a hit, the target takes an extra 10 (3d6) damage.
Legendary Actions
Snap. Make one Bite attack.
Blur (Costs 2 Actions). The rabbit gains disadvantage to be hit until the start of its next turn.
Combat Notes
• It should win initiative.
• It should down the wizard first.
• It should reposition constantly.
• It should crit at least once in the encounter.
• If the party treats it like “just a bunny,” someone loses their head.
The Cave of Caerbannog
The Cave of Caerbannog appears serene at first glance — moss-covered stones, soft grass at the entrance, a quiet stream nearby. Within, however, the air smells faintly of iron and old blood. Bones — many very cleanly severed bones — lie half-hidden in shadow.
Within its lair, the rabbit becomes nearly unstoppable. Narrow crevices riddle the walls, allowing it to vanish and reappear in a blink. The stone floor grows slick with fresh blood at its whim.
Those who mock the beast often perish first.
Regional Effects
The region within 1 mile of the cave is warped by the rabbit’s presence: Small animals avoid the area entirely. The grass near the cave entrance is unnaturally lush and green. At dawn, the cave entrance appears harmless and inviting. Severed bones are found unnaturally clean, as though polished.
Optional Lair Actions (The Cave of Caerbannog)
On initiative count 20 (losing ties), the rabbit may cause one of the following:
Blood-Slick Stone
- The floor becomes treacherously slick with fresh blood in a 20-foot radius centered on a point the rabbit can see.
- Creatures other than the rabbit in that area must succeed on a DC 15 Dexterity saving throw or fall prone.
- The area becomes difficult terrain until initiative count 20 of the next round.
Sudden Burrow
- The rabbit vanishes into a narrow crevice in the cave wall and reappears in another unoccupied space within 40 feet.
- This movement does not provoke opportunity attacks.
- If it appears adjacent to a creature, it may immediately make one Bite attack as part of this lair action.
Ossuary Tremor
- The cave walls tremble, and skulls tumble from narrow ledges above.
- Up to three creatures the rabbit can see must make a DC 16 Dexterity saving throw.
- On a failure, a creature takes 3d8 bludgeoning damage and is knocked prone. On a success, it takes half damage and isn’t knocked prone.
Wrongness of the Warren
- A pulse of unnatural dread ripples through the cavern. Each hostile creature within 30 feet of the rabbit must make a DC 15 Wisdom saving throw.
- On a failure, the creature: Has disadvantage on its next attack roll. Cannot willingly move closer to the rabbit until the end of its next turn. On a failure by 5 or more, the creature is frightened until the end of its next turn.
Return to Ye Olde Shoppe of Magicks
Members of DnD Beyond can add this item to their campaigns.
Killer Rabbit of Caerbannog is inspired by the final boss in Monty Python and the Holy Grail. Killer Rabbit of Caerbannog base images were built using ChatGPT using prompts by Alien Graphics ©2026 Alien Graphics
All verbiage is ©2026 Alien Graphics and all imagery is ©2026 Alien Graphics and shared under the CC BY-NC-SA
Vulcan Stev's Database 