You know what this game needs? More rats!

Ratfolk
Climate/Terrain: Any Land
Frequency: Uncommon
Organization: Swarm
Activity Cycle: Nocturnal
Diet: Omnivore
Intelligence: Average: 9-10
Treasure: Varies
Alignment: Varies
No. Appearing: 1+(generally 3-12)
AC: 7
Mv: 12
HD: 1 or 2
Thac0: 20 or 18
#AT: 1
Dmg: By weapon
Special Attacks: Thieving skills or berserker rage.
Special Defenses: None
Size: M(6 feet tall)
Magic Resistance: 0%
Morale: Unsteady(5)
XP: 35

Ratfolk look like the man-rat hybrid forms of the were-rats. This has often caused ratfolk to be persecuted. Ratfolk speak their own language, and a large number also speak common, goblin, jermlaine, and undercommon.
Combat: Ratfolk come in two varieties; Feral and Civilized. Civilized Ratfolk prefer to use rogue weapons and tactics. Most adult civilized ratfolk have the thieving skills of a 3rd level thief. Feral Ratfolk, being about a head larger than their "civilized" kin, tend to use brute force, and thus prefer 2 handed swords, spears, great axes, and the like. Once per day they can enter a berserker rage, gaining a +1 bonus to attack, a +2 bonus to damage, and they regenerate 1 damage per round as long as they're above 0 hp. They'll continue fighting in this state until all non-ratfolk in the immediate vicinity are incapacitated. Ratfolk are generally a cowardly lot, and they don't attack unless they feel they have a clear advantage in a fight.
Habitat/Society: Ratfolk are social beings and gather into clans. The Feral ratfolk tend to be seafarers, building settlements on hidden or conquered islands, and sending forth their longships to raid others. Civilized Ratfolk prefer to dwell underground in the sewers and catacombs of major cities, but many end up traveling in brightly colored wagons moving from location to location, surviving as entertainers and thieves.
Ecology: Ratfolk are omnivores, and some of the civilized kind make passable, if lazy, farmers. The civilized kind generally avoid eating sentient creatures(unless fresh corpses are available) but feral ratfolk often raid human settlements solely so they can eat the people.