Eidolon question

[Bao Hadir]

Does a summoner's eidolon follow the traits on the Outsider page?

[Jeff Merola]

Eidolons use the stats listed in the Eidolon section and are outsiders "for the purpose of determining which spells affect them."

If you'll compare the Eidolon stats (both normal and Unchained) to Outsider traits, though, you'll find they match perfectly with one exception: Eidolons are not automatically proficient with all simple and martial weapons.

[DM-DR]

Yes; however, there are a few differences as described in the Eidolon section on the summoner class (such as when they are sent back vs. killed).