rare n small animal 

Perception +5; low-light vision, scent (imprecise) 30 feet

Skills Acrobatics +5, Athletics +3 (+5 to Climb or Swim), Stealth +7

Str +1 Dex +3 Con +2 Int -4 Wis +1 Cha -3

AC  16; Fort +6, Ref +7, Will +3

HP 15; Immunities cold

Speed 30 feet, climb 10 feet

Melee [>] jaws +7 (agile, finesse), Damage 1d6+1 piercing plus 1 cold damage

Icy Death When an icy rat is slain, its body explodes in a burst of frozen fur and bone, dealing 2d4 cold damage to all adjacent creatures (DC 14 basic Reflex save).

The Fall of Plaguestone, page 31.