Swarm Evolution
Feat 17
Source Player Core pg. 69
Prerequisites Swarm Exile Shirren
Whether gradual or in an instant burst of glorious evolution, you've metamorphosed into a powerful Swarm-like creature. You gain a +2 status bonus to saves against fear, and you gain acid resistance equal to half your level. You can cast mask of terror as a 7th-rank primal innate spell once per day.