You need some more aggressive and better animal companions/familiars. If you were using an Imp or Hell Hound then people would probably leave the familiar alone. Also, using a crocodile that bites at players and goes straight into a grapple against them if they get too close would be very effective. (Lets see a low lvl sorcerer try to deal with a buffed up crocodile ripping apart their leg with it's jaws and then grappling them.)