You may get a Wurmstone or a True Dragonstone as reward from your faction, the Wurmstone turns you into a Wurm and the True Dragonstone turns you into a Dragon looking cutey!
Using the Dragon form will give you a 10% chance of an Ancient dragon spirit joining you in combat, while being in Wurm or Dragon form will give you a 20% chance of a familiar joining you in combat.
Failing that it is a 5% chance of a familiar joining you in combat … as you can see getting enough fame or doing the quests to get the dragonstone or wurmstone rewards gives a nice advantage in combat.