I was trying to save rolls to make those grapple checks go faster... Oops. Consider them for "next round."
Round one, one arrow demon summoned 5 dretches, second arrow demon fired 4 shots from 2 bows (woo!) at Evard, conflagration ooze confused the monk, who decided to attack the mighty Cohen. Top of the round, Evard announced tentacles and, receiving no damage, successfully fired off his spell, entangling 3 out of 5 dretches, both arrow demons, and the ooze.
Round 2. This forced them all to make grappling checks against the dratted tentacles, and they each failed.
One free dretch attempted to scare Cohen, but dretches are pretty stupid, so it failed. The second free dretch made a stinking cloud atop the heroic party (gag). The DM failed at file versioning, so the circumference is included in the forthcoming file. Mook tried to OHKO Cohen, but missed, and Cohen tripped him.