Infested Demon
These lurching horrors stink of rotting flesh. When they are cut down, their carcasses break open and waves of writhing invertebrates spill out.

CR6 Infested Demon 15 - Large Demon12 HP81 Initiative-1 Speed20(4) AC16(T8,FF16) Glaive+10(d8+5+2d6swarm) SQ DR5/slashing, reach10, hivedeath Abilities21,8,-,-,10,1 Saves+4/+3/+8 Rewards - 1500 souls, 50% titanite splinter

Centipede Swarm - Diminutive/Large Vermin9 HP31 Initiative+4 Speed-20(4) AC18(T18,FF14) Swarm 2d6+d4 dexterity (fortitude DC13) SQ weapon immunity, swarm traits, vermin traits, tremorsense, nausea DC13(lose standard action) Abilities1,19,8,-,10,2 Saves+5,+7,+3