This rat startles upon detection. Within seconds, the one rat becomes four, and then the four quickly multiply into sixteen rats.
Doppelrat CR 1
Speed 15 ft., climb 15 ft., swim 15 ft.
Melee bite +6 (1d3–4)
Special Attacks arcane mitosis, disease
Str 2, Dex 15, Con 11, Int 2, Wis 13, Cha 2
Base Atk +2; CMB +2; CMD 8
Feats Weapon Finesse
Skills Acrobatics +2 (+6 jump), Climb +10, Stealth +19, Swim +10; Racial Modifiers +4 Stealth, uses Dex for Climb and Swim
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. Each duplicate appears in the same square as any other rat, can take a move or standard action the round it appears, and has 1/4 the main rat’s current hp (minimum 1). After the last multiplication of rats, all surviving clones perish in 8 rounds. If the original doppelrat dies, its arcane mitosis ends, but the clones remain for 8 rounds. A doppelrat may not use this ability until 10 minutes have passed from the previous use.
Degenerate cloning—injury; save Fort DC 11; onset 1 day; frequency 1/day; effect 1d3 Str damage, 1d3 Con damage, and the victim becomes shaken for 1 hour (Will DC 11); cure 2 consecutive saves. Doppelrats created through arcane mitosis can also transmit this disease.
Environment any temperate
Organization solitary or pair
The result of clone gone awry, a doppelrat uses short-lived duplicates to overwhelm its competitors. An easy battle against a single rat soon spirals out of control as the rat clones itself into a swarm and hides while combat rages.
Rat-bitten survivors suffer from a frightening disease, sloughing off a stillborn clone each day as their own vitality fades. Clones created by the disease 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 their normal cousins and natural predators. A cat that has survived an encounter with a doppelrat avoids any other doppelrats it comes across. The rats have an instinctual sense for others of their kind; helpful, since litters born to doppelrat parents produce only 1 such creature out of 10. The rest provide sustenance for their parents and siblings. The creatures have a straightforward method of combat: spawn as many clones as it can, and then escape 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. In cities with known doppelrat lairs, magistrates hire spellcasters to scour alleys and sewers and quickly obliterate any rats they find. Less than scrupulous spellcasters who manage to capture a live doppelrat have used this to their advantage by promising to rescue the town from the explosion of rats for an exorbitant fee. Terrifying rumors of a dire doppelrat have never been substantiated.