Wererat Rat Form (CR 2)

Small Humanoid (Human and Shapechanger)
Alignment: Always lawful evil
Initiative: +3 (Dex); Senses: low-light vision, scent, Listen +4, and Spot +4

AC: 17 (+1 size, +3 Dex, +3 natural), touch 14, flat-footed 14
Hit Dice: 1d8+1 plus 1d8+2 (12 hp); DR: 10/silver
Fort +6, Ref +5, Will +4
Speed: 40 ft.
Space: 5 ft./5 ft.
Base Attack +1; Grapple -2
Attack: Bite +6 melee
Full Attack: Bite +6 melee
Damage: Bite 1d4+1 plus disease
Special Attacks/Actions: Curse of lycanthropy, disease
Abilities: Str 13, Dex 11, Con 12, Int 10, Wis 11, Cha 8
Special Qualities: Alternate form, Rat empathy
Feats: Alertness; Dodge; Iron Will; Weapon Finesse
Skills: Climb +11, Handle Animal +3, Hide +8, Listen +4, Move Silently +4, Spot +4, and Swim +11
Advancement: By character class
Climate/Terrain: Any land and underground
Organization: Solitary, pair, pack (6-10), or troupe (2-5 plus 5-8 dire rats)
Treasure/Possessions: Standard

Source: Monster Manual

Lycanthropes in their natural forms use whatever tactics are favored by their people, though they tend to be slightly more aggressive. Lycanthropes in animal or hybrid form fight like the animal they resemble.

Wererats can assume a hybrid form as well as an animal form.

Alternate Form (Su): A wererat can assume a bipedal hybrid form or the form of a dire rat. The bipedal form is Medium-size with head, torso, and tail identical to those of a rat, although the limbs remain human. The rat form is 2 feet long from nose to rump and is preferred for travel and spying on potential victims.

Skills: A wererat in rat or hybrid form uses its Dexterity modifier for Climb checks.

Shapechanger Subtype

A shapechanger has the supernatural ability to assume one or more alternate forms. Many magical effects allow some kind of shape shifting, and not every creature that can change shapes has the shapechanger subtype.

Traits: A shapechanger possesses the following traits (unless otherwise noted in a creature's entry).