Rat

Common rats measure 5 to 12 inches, not counting the tail. The slim black rat runs about 8 inches with a tail just as long or longer, a pointed snout and tall ears; it is really charcoal with brown blotches above and pale below. It climbs (climb 3) and leaps well but never swims. The heavier brown rat, the sewer or wharf rat, is 5 to 10 inches with a shorter tail and smaller eyes and ears, in gray, white, black or mottled coats. It cannot climb but swims (swim 3) and digs well. In a shared building, black rats hold the attic floors and brown rats the ground level and cellar.

Rats flee anything larger unless trapped or starving, and then they will tackle almost anything. Their bites are filthy: each carries a 5% chance of a serious illness, avoided with a save vs. poison. Fire frightens them, though real hunger overcomes that.

Run a big swarm as one monster. One example covers 10 by 10 feet, has 4 HD and automatically inflicts 4 damage each round on small creatures within it. Weapons barely hurt it, but area spells or flaming oil work well, and once its hit points are gone the swarm scatters and stops dealing that mass damage.

Food is everything to a rat. Packs tunnel into stores and nest almost anywhere, shredding wood, fabric or paper for bedding.

Both kinds eat anything and breed three to five times yearly; brown rats bear 2d4+6 per litter, black rats only 5-6. Brown rats are the meaner of the two and can gnaw through lead pipe. Either kind lives two to four years.

Brush rats, also called pack rats or trade rats, belong to the gentler wood rat family. Slate above and white below and about brown-rat size, they make woodland nests or dens and pilfer small shiny objects for their hoards. These plant-eaters never attack humans, carry no disease, and take well to training.

Giant rats infest crypts, dungeons and graveyards, tunneling to fresh burials before the ghouls can. They look like bloated brown rats, brown-black with white bellies and short tails. Each bite risks a 5% chance of debilitating disease, prevented by a save vs. poison. They avoid strong groups unless starving or driven by a master such as a vampire or wererat, flee fire unless hunger or magic compels them, and fight as well in water as on land.

Osquips are hairless, dog-sized rodents with huge heads, big teeth and pale yellow hides. Six legs is typical, though 25% have eight and 5% have ten. Their hidden tunnels let them burst out so fast that foes take -5 on surprise, and their teeth chew through stone. Fearless and territorial, they do not dread fire, but half drown in water while the rest paddle at movement 1. They are hard to tame, though jermlaine and some wizards have bribed them with gems for their shiny-object hoards. Their leather is soft and waterproof, and their teeth serve in digging magic.