Question on using familiars and the Bestiary?

[The Imperator]

Reading through PFS rules, it appears you need any book you wish to use. Does this mean I need to purchase the correct Bestiary to use a Wizard's familiar, since the stats proper for the creature are not found in the Core Rulebook? I would assume so, but I was just curious and wanted to find out before I bought the Bestiary.

[Humphry B ManWitch]

if you don't use the familiar in combat it wont be an issue

[The Imperator]

Thank you :)