The Shrapnel Rat

A few years back I wrote a post of random encounter tables that included a monster called the "Shrapnel Rat" that could be found living in the Mega-City of Prospero's Underhive. It was something I was inspired to write from the video game Gears of War. Believe it or not the explosive rat was also an idea used by the Special Operations Executive in WWII. It didn’t end up panning out the way they wanted, but hey, that just a weird thing to read about. Fact is often stranger than fiction as they say. Anyway the idea has always stuck with me so I figured I'd finally write it up. The Swords & Wizardry version is called a Suicide Rat, that is often confused with the Giant Rat from the Core S&W book, and the Shrapnel Rat in Stars Without Number format.

Suicide Rat: Swords & Wizardry Version

The origin of the suicide rat are disputed. According to the Sages of Nemite, these rats were created as a weapon in a bloody drawn out war. Created to infiltrate enemy positions, and booby trap battle fields. If a well known tavern legend is to be believed, the rats were crafted by a vengeful wizard. According to this tale his brother, a cotter in the town Ulthar, was murdered by a pack of felines. What ever the truth is these creatures have been spreading far and wide across the lands.

Shrapnel Rat: Stars Without Number version
The Mega City of Prosperos Underhive, a never ending catacomb of death and despair is the home to many dangerous creatures. Shrapnel Rats have quickly risen to the top of this deadly underground ecosystem due to the multitude of ambush and nesting sites. A number of therories have been circulated as to where these deadly creatures came from. One story by a Hiver suggests that they were purposefully created to kill off those lining in the dark service tunnels and sewers. An undisclosed corporate whitleblower stated that the rats were part of a Black Lab experiment that went out of control and escaped into the environment. A xenobiologist specializing in the Underhive believes that this just might be part of the evolution process in such a hostile environment.

Suicide Rat: Swords & Wizardry Statistics

Armour Class: 7 [12]

Hit Dice: 1d4 Hit points

Attacks: Bite (1d4) or Explosion (2d6) 10' radius,

save for half damage.

Saving Throw: 18

Special: Implant Embryos

              Explosion 

Move: 12

Challenge Level/XP: 1/15

Shrapnel Rat: Stars Without Number Statistics

Armour Class: 7                           No. Appearing: 1-8

Hit Dice: 1/2                                  Saving Throw: 15+

Attack Bonus: +1                         Movement: 20'

Damage: 1d4 Bite                         Morale: 8

                2d6 explosion                            

Special: Implant embryos

Rules 

These rules can be used for whichever version of the game you are playing.  

Explode: After a successful attack the rat has been primed and will explode 1d6 rounds later. It may also explode if its surprised or frightened. The rat will charge its target (+2 to attack) and explode immediately afterwards. Damage that reduces the rat's hit points to zero or lower causes the rat to explode. An exploding rat deals 2d6 damage to everyone in a 10' radius of itself (successful save for half damage).

Implant Embryos: Any creature damaged by the exploding makes a saving throw. On a failure the creature has been implanted with suicide rat embryos. Every day the creature must make a new saving throw. On a failure the target loses 1d4 Constitution points. Once three successful saves have been made or the a cure disease spell has been cast the creature is fully cured. If the creatures's Constitution score reaches zero before it's cured, 1d6 regular rats will chew, claw, and burst out of it's stomach. If these newborn rats are not being threatened they will feed on the corpse, otherwise they attack and/or flee for safety. These newborn rats have the same statistics, but cannot yet explode or implant embryos. After a 24 hour period they will have matured into full blown suicide/shrapnel rats themselves. For Stars Without Number the Implant Embryo ability is considered a disease with a Toxicity 8 and a Virulence of 3, all other effects remain the same.