The Stars are Fire
Yeah, rats made it to space. And against all expectations, one strain evolved in the harsh radiation and zero-G environments that would kill humans not protected by medical intervention. Space rats are furless, about two feet long, sport a truly prehensile tail, and can quickly change their shade of their skin to blend in to their surroundings. They can also drop into a state of extreme torpor that allows them to survive stints of vacuum exposure lasting several days.
Space rats are vermin, and any spacecraft or space station that hosts a nest must deal with constant issues from the rats burrowing into systems, stealing food and water, and causing systems to break down, even critical ones. They're also vicious when cornered.
Motive: Defense, reproduction
Environment: Anywhere humans live in space (Space)
Health: 5
Damage: 3 points
Movement: Short; short when climbing or gliding through zero G
Modifications: Stealth and perception as level 5
Combat: Space rats flee combat unless cornered or one of their burrows is invaded. Then they attack in packs of three or more, and from an ambush if possible. One space rat pack attacks the victim as a level 3 creature inflicting a moderate wound (5 points) with claws, while another pack helps the first, or attempts to steal a food item or shiny object from the character being attacked. To resist theft while being attacked on two fronts, a target must succeed on a Speed defense roll hindered by two steps.
Interactions: Space rats are slightly more intelligent than their Earth-bound cousins, though true interaction is not possible. On the other hand, sometimes their behavior seems spookily sapient.
Uses: Space rats assemble crude nests in out-of-the-way supply closets or in hard-to-reach system interiors, but often enough, end up shorting out weapons or life support. Sometimes, they get into the hold and eat anything edible in the cargo.
Loot: Some percent of valuable equipment stolen on the spacecraft or station finds its way to space rat nests.
GM Intrusion: Another rat unexpectedly pops out of panel on the wall or ceiling and screeches so loudly the PC must succeed on an Intellect defense roll hindered by two steps or be dazed until the end of their next turn from the surprise. Dazed creatures are hindered on all tasks.