While some clans (Inuzuka) do have familiars that work a little differently then summons, please try not to use them. It was really a "canon" based creation, and we certainly don't want to have it eventually turn into a bad custom fad along the lines of stat increasing jutsu, chakra reducing jutsu, and tailed demons (every Naruto RPG has been haunted by one of these).

If you do pursue such a familiar, don't be offended if it gets turned down or you're asked to just make it like a regular summon. Remember summons here can be anything from animals, to light, to flying chakra wielding genitalia *my personal favorite*. Clan familiars may be allowed so long as it is a fundamental part of the clan, like a puppet to a puppet master, or the canine to the inuzuka. But just know that a whole lot of them may not be allowed as they could lead to abuse and complications in the future.