From Pathfinder Society Quest #16: The Winter Queen's Dollhouse, which isn't enabled.

Weak Giant Mouse

CREATURE -1

Perception +6

Skills Acrobatics +3, Athletics +1, Stealth +4

Str +0, Dex +3, Con +2, Int -4, Wis +0, Cha +2

AC 13; Fort +1, Ref +7, Will +1

HP 4

Skittish

Trigger The giant mouse is hit with a melee attack

Effect The giant mouse takes a step after the effects of the triggering attack are resolved.

Speed 25 feet

Melee Bite +4 (finesse), Damage 1d4 piercing

Pathfinder Society Quest #16: The Winter Queen's DollhouseOGL