I have two classes that have familiars: black mages and white mages. Black mages are roughly like wizards, white mages are roughly like clerics. If you've played the Final Fantasy games, you'll recognize the names, but that's about where the similarity ends. So anyone who wants a character with a familiar can have it. The familiars are exactly the same as in the Core Rules, too, so if you want some 1337 ninja familiar (like the higher level ones in Magic of Faerun), you can have it, your GM willing.