n small animal 

Perception +6; darkvision, scent (imprecise) 60 feet

Skills Acrobatics +6, Stealth +8

Str +1 Dex +3 Con +1 Int -5 Wis +1 Cha -1

AC  16; Fort +6, Ref +8, Will +4

HP 20

Scurry [R] Trigger The giant cockroach is targeted by a melee attack; Effect The giant cockroach gains a +2 circumstance bonus to AC against the triggering attack. After the attack resolves, the cockroach Strides, Climbs, or Flies up to 10 feet.

Speed 25 feet, climb 25 feet, fly 15 feet

Melee [>] mandibles +8 (agile, finesse), Damage 1d6+1 piercing

Bestiary 2, page 53.