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Doppelrat (3pp)

Tiny monstrosity, unaligned

Armor Class 13
Hit Points 22 (5d4 + 10)
Speed 15 ft., climb 15 ft., swim 15 ft.

2 (-4) 17 (+3) 14 (+2) 2 (-4) 13 (+1) 2 (-4)

Saving Throws Dex +5
Skills Stealth +5
Senses darkvision 60 ft., passive Perception 11
Challenge 2 (450 XP)

Special Traits

  • Keen Smell. The doppelrat has advantage on Wisdom (Perception) checks that rely on smell.


  • Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 1 piercing damage.
  • Arcane Doubling (recharges after 10 minutes). A doppelrat under duress creates clones of itself at the beginning of its turn. Each round for 4 rounds, the number of live doppelrats quadruples but never exceeds 20. For example, when the doppelrat triggers arcane doubling, 1 rat becomes 4; at the start of the rat’s next turn, those 4 become 16; and at the start of the rat’s third turn, those 16 become 20, the maximum allowed. If one of the duplicates was destroyed between the original doppelrat’s 1st and 2nd turns, then the surviving 3 would become 12, and so on. Each duplicate appears in the same space as any other rat, can either move or take an action the round it appears, and has 4 hit points and AC 13. Any surviving duplicates perish 1 minute (10 rounds) after the first ones were created. If the original doppelrat dies, its clones stop duplicating but the pre-existing clones remain until their time expires. A creature can identify the original doppelrat from its duplicates by taking the search action and making a successful DC 15 Intelligence (Nature) or Wisdom (Perception) check.
  • Doppeling Disease. At the end of a dopplerat encounter, every creature bitten by a doppelrat or its duplicates must succeed on a DC 12 Constitution saving throw or contract the degenerate cloning disease. During each long rest, the diseased creature grows and sloughs off a stillborn clone. The doppeling process leaves the diseased creature incapacitated for 1 hour, unable to move and barely able to speak (spellcasting is impossible in this state). When the incapacitation wears off, the creature makes a DC 12 Constitution saving throw; it recovers from the disease when it makes its second successful save. Humanoid clones created by the disease cannot be brought to life in any manner.


This rat startled the moment it knew it was seen. Within seconds, the one rat became four, and then the four quickly multiplied into sixteen rats.


The result of a clone spell gone awry, a doppelrat uses short-lived duplicates to overwhelm its adversaries. An easy battle against a single rat can quickly spiral out of control as the doppelrat clones itself into a swarm- and the original rat may hide while combat rages.

Stillborn Clones. Those who survive a doppelrat’s bite suffer from a frightening disease, sloughing off a stillborn clone each day as their own vitality fades. These clones cannot be raised from the dead in any manner. Doppelrats settle in large city alleys and sewers after they have killed off or driven out normal rats and natural predators. A cat that survives an encounter with a doppelrat avoids any other doppelrats it meets. Doppelrats can sense others of their kind; helpful, since doppelrat litters produce only one truebred creature out of ten. Their parents and siblings devour the others.

Clone and Run. In combat, they spawn as many clones as they can, and then flee while the copied rats swarm their opponent. By succeeding at a Perception check opposed by the doppelrat’s Stealth check, a character can discern the original from all the clones.

City Bounties. In cities with known doppelrat lairs, magistrates hire spellcasters to scour alleys and sewers and obliterate any rats they find. Shady spellcasters who capture a live doppelrat have blackmailed such magistrates by promising to rescue the town from the rats for an exorbitant fee.

Section 15: Copyright Notice

Tome of Beasts. Copyright 2016, Open Design; Authors Chris Harris, Dan Dillon, Rodrigo Garcia Carmona, and Wolfgang Baur.