From publisher blurb:
The Pitter-Patter of Tiny Feet!
Or the flutter of diminutive wings and the glint of beady eyes, or even the slavering of a hundred miniature mouths, the early warning signs of a swarm nearby are easily overlooked. Often seen as a low-level dungeon annoyance, swarms are a flexible idea supported by rules that can be applied to adventures of any scope or level. All you need as a few extra examples!
Within the Swarminomicon you’ll find:
New Swarms: You want swarms? We offer 40 new swarms, from the CR 2 aquatic electric eel swarm to the land-killing CR 20 pestilence swarm, including undead, glyphs, and swarms of baby abberations.
Swarm Feats: Just because you are a collection of thousands of disparate creatures doesn’t mean you can’t learn a few tricks. From the fireball-dodging Dispersing Evasion to the deadly Swarming Vital Strike, these feats allow a GM to fine-tune a swarm to provide the encounter desired.
Swarm Spells: Whether you want to summon some of the new sets of swarms we present, or turn your swarms into a wall, we give you the spells you need to get the most from your new swarms.
Swarm On!