Originally Posted by von Tortrix
Can a Summoner's Eidolon take the feat 'Improved Natural Attack' multiple times, and have its effects stack on the same natural attack? I couldn't find any ruling on this in the Bestiary.
There is no typed limit as to the number of times the feat can be taken, so by RAW it should stack.
I'll note here however that DMs might not like this and the 3.5 version of the feat didn't stack. Be on the look out for errata of this feat in the future.