uncommon conjuration sorcerer 

Bloodline demonic

Cast [>] to [>>>] (somatic, verbal)

Range 120 feet; Area 5-foot burst or more

Saving Throw basic Fortitude; Duration 1 minute

Ground in the area turns swampy and fetid. The area is difficult terrain. The sludge at the bottom of the morass animates into diminutive sludge beasts that have a demonic appearance. These don't function as normal creatures, but they swarm over creatures in the swamp and exude a noxious stench. The swamp deals 1d6 poison damage; creatures that end their turn in the area must attempt a basic Fortitude save. You can increase the number of actions it takes to Cast the Spell. For each additional action, increase the burst's radius by 5 feet.

Heightened (+2) The damage increases by 1d6, and the initial radius increases by 5 feet.

Core Rulebook, page 405.