Getting ready to play my first Summoner.
If an eidolon has the bipedal form, does he count as a humanoid for spells such as Enlarge Person?
No. Many outsiders are humanoid, but they all have the outsider type. However, if you are casting enlarge person on your eidolon, you can affect it as if it was humanoid, because of the "Share Spells" class feature.