Salvage Rat (CR 1)

Tiny Construct
Alignment: Any (same as creator)
Initiative: +2 (Dex); Senses: low-light vision
Languages: Cannot speak

AC: 17 (+2 size, +2 Dex, +3 natural), touch 14, flat-footed 15
Hit Dice: 1d10 (5 hp)
Fort +0, Ref +2, Will +1
Speed: 15 ft., burrow 5 ft.(through metal only), climb 15 ft.
Space: 2-1/2 ft./0 ft.
Base Attack +0; Grapple -10
Attack: Bite +4 melee
Full Attack: Bite +4 melee
Damage: Bite 1d4-2 plus rust
Special Attacks/Actions: Rust
Abilities: Str 6, Dex 15, Con -, Int 2, Wis 12, Cha 2
Special Qualities: Construct traits, familiar traits
Feats: Weapon Finesse
Skills: Balance +10, Climb +10, Hide +8, and Move Silently +8
Climate/Terrain: Any
Organization: Solitary
Treasure/Possessions: None

Source: Dragon #341

Rust (Ex): A salvage rat that makes a successful bite attack causes the target's metal armor to corrode and lose some of its protective value. Each bite reduces the armor bonus granted by -1 until the armor grants no bonus and is destroyed. Magic armor receives a DC 10 Reflex save to avoid this effect. The save DC is Constitution-based. This bite does not affect shields, weapons, or other pieces of metal equipment.

Skills: Salvage rats have a +4 racial bonus on Hide and Move Silently checks, and a +8 racial bonus on Balance and Climb checks. A rat can always choose to take 10 on Climb checks, even if rushed or threatened. A salvage rat uses its Dexterity modifier instead of its Strength modifier for Climb checks.

In combat, salvage rats dart from foe to foe hiding in the shadows and biting whenever possible while avoiding drawn out melee confrontations.