SRD:Wererat

Wererat
A wererat in humanoid form tends to be a thin, wiry individual of shorter than average height. The eyes constantly dart around, and the nose and mouth may twitch if he or she is excited. Males often have thin, ragged mustaches.

Combat
In animal form, wererats avoid combat, preferring to use their dire rat shape for skulking and spying. In hybrid form, a wererat fights with a rapier and light crossbow.

Alternate Form (Su): A wererat can assume a bipedal hybrid form or the form of a dire rat.

Curse of Lycanthropy (Su): Any humanoid or giant hit by a wererat’s bite attack in animal or hybrid form must succeed on a DC 15 Fortitude save or contract lycanthropy.

Disease (Ex): Filth fever; bite, Fortitude DC 12, incubation period 1d3 days, damage 1d3 Dex and 1d3 Con. The save DC is Constitution-based.

Rat Empathy (Ex): Communicate with rats and dire rats, and +4 racial bonus on Charisma-based checks against rats and dire rats.

Skills: A wererat in rat or hybrid form uses its Dexterity modifier for Climb or Swim checks. It has a +8 racial bonus on Climb checks and can always choose to take 10 on a Climb check, even if rushed or threatened.

Wererats have a +8 racial bonus on Swim checks from their dire rat form.

Feats: Wererats gain Weapon Finesse as a bonus feat.

The wererat presented here is based on a 1st-level human warrior who is a natural lycanthrope, using the following base ability scores: Str 13, Dex 11, Con 12, Int 10, Wis 9, Cha 8.

See Wikipedia Entry: Lycanthrope