This writhing mass is formed of countless rats that have fused into a single being.
AC 12, touch 12, flat-footed 10 (+2 Dex)
Speed 15 ft., climb 15 ft., swim 15 ft.
Str 10, Dex 15, Con 13, Int 2, Wis 13, Cha 2
Discorporate (Ex) A rat king dies when reduced to 0 hit points. When a rat king dies, unless its body has been completely destroyed, its remains immediately become a normal, full-strength rat swarm.
Disease (Ex) Filth fever: Melee touch—injury; save Fort DC 12; onset 1d3 days; frequency 1/day; effect 1d3 Dex damage and 1d3 Con damage; cure 2 consecutive saves. The save DC is Constitution-based.