Echoes of the First World (Teamwork)Source Inner Sea Races pg. 205
Your fey heritage is strong, and it grows stronger when you’re near another of your kind.
Prerequisites: Knowledge (nature) 2 ranks, gnome subtype.
Benefit: While you’re adjacent to an ally who has the gnome subtype and who also has this feat, you gain DR 2/cold iron, and you count as fey instead of humanoid for the purposes of effects that target creatures by type. You still count as having the gnome subtype, however.