Imp Swarm

[Ultimagus]

Hey folks, I'm looking at designing an Imp Swarm to use at some point in time. Preferably still maintaining some of the impish nastiness, like being able to go invisible at will, and poison. Thoughts? Ideas on what the CR might be? Any other advice on making variant swarms?

[Dragonborn3]

There is always the Swarm template. :)

[Yours is mined]

Greg A. Vaughan came up with the “Dretch Megaswarm” for Pathfinder in Frog God Games’ Slumbering Tsar – The Hidden Citadel, Part 5.

CR 12, 136 hp, usual swarm traits + Dretchy goodness badness

Looks quite nasty, but I haven’t seen one in action.

Might be a reasonable point of reference for your Imp swarm.

[Turelus]

As mentioned above there are megaswarm rules from Vaughan.

They're published in Tome of Horrors 4 as well.