Shape shifter

You're a spell caster, this is your very last year at the academy. You professor announces you will be summoning your familiars. The rarer your familiar, the more powerful you are or will become. The shape shifter is the rarest and most powerful familiar, it has only ever been summoned once in history. You summoned a shape shifter and it is not anywhere near similar to the other familiars. They are always males, they are one of the only familiars that can talk, you can name it, and you can chose whichever kind if relationship you want with it. However, it is it's own conscious being, devoted to protecting and serving you.