Doppelrat

The result of a swarm of rats devouring a wizard’s clone, doppelrats have gained the magical ability to create short lived clones that they use for self defense. When faced with a threat, even a single doppelrat can quickly cause a fight to spiral out of control, as it creates more and more duplicates to overwhelm its adversaries. The original can be lost among the swarm of duplicates, often escaping while the predator chews through the clones, and many predators are satisfied with their catch, if they get a clone or two. Of course, many smaller predators, such as cats, snakes, and birds of prey, can be quickly killed by a swarm of clones, and a doppelrat infestation can eliminate most natural predators quickly, allowing their population to grow.

Perhaps more concerning for survivors of a doppelrat attack is the doppeling disease they spread. Those who are bitten may be infected, and the effect of it is deeply disturbing to many. Victims may attempt to avoid resting, as doing so causes their body to produce an entire clone of them, the copy splitting off in a painful, draining hour long experience. For good or ill, the clone is stillborn, no life carried in it, but splitting off your own corpse each day is not a pleasant experience. Family members finding a corpse of a loved one next to a living version may mistake the victim for a doppelganger or other shapeshifting monster, thinking the original is dead, and more than one doppeling disease patient has been tragically killed by a family member while trying to recover from birthing off a clone.

Inspired by the Tome of Beasts 1. This post came out a week ago on my Patreon. If you want to get access to all my monster conversions early, as well as access to my premade adventures and other material I’m working on, consider backing me there!

Pathfinder 2e

Doppelrat Creature 2
Rare, Tiny, Beast
Perception +8; low-light vision, scent (imprecise) 30 feet
Skills Acrobatics +7, Stealth +9
Str -4, Dex +3, Con +2, Int -4, Wis +1, Cha -4
AC 17; Fort +6, Ref +9, Will +7
HP 20
Speed 15 feet, climb 15 feet, swim 15 feet
Melee jaws +7 (agile, finesse), Damage 1d4 piercing plus Doppling Disease
Arcane Doubling [3 actions] (arcane); Frequency once per day; Effect For the next 4 rounds, the doppelrat and each of its clones create 3 clones of itself that appear adjacent to it, to a maximum of 19 clones. Each clone has the doppelrat’s stats, except it only has 2 hp. Any surviving clones die 1 minute after the doppelrat uses this action. If the original doppelrat dies, the clones stop duplicating but remain until their time expires. Use the doppelrat’s Stealth DC against attempts to Seek or Recall Knowledge to identify the original.
Doppling Disease (disease); Saving Throw DC 15 Fortitude; Onset 1 day; Stage 1 After the creature’s next rest, it is incapacitated for 1 hour as it grows and releases a stillborn clone; it is drained 1 from the experience.

13th Age

Doppelrat
2nd level spoiler [beast]
Initiative: +7
Doppeling Bite +7 vs. AC – 2 damage.
Natural 16+: The target gets afflicted by doppeling disease. Each time it takes a full heal-up, it must roll a normal save. On a failure, it sheds off a stillborn clone during the full heal up, and regains 1 less recovery. After 3 successes (they don’t have to be consecutive), the character recovers from the disease.
Arcane Doubling: 1/battle as a standard action, the doppelrat can start duplicating itself. At the start of each of its turns, the rat produces a number of duplicates of itself equal to the escalation die, to a maximum of 8. Each duplicate has the same stats as the doppelrat, except it only has 2 hp. Whenever an enemy tries to target the original doppelrat, it must succeed on a DC 15 skill check to identify it from the duplicates; on a failure, it attacks at random.
Wall-Crawler.
AC 20 PD 17 MD 11 HP 26