Grand Familiar

You have invested a vast amount of power to enhance the forms that your familiar can adopt and what it is capable of. Your familiar can be any Beast, Dragon, Monstrosity, Ooze, Plant, or Undead with a CR equal to or less than your total level divided by 3 rounded down. You familiar may also multiattack.

With your DM's approval, you may use this feat to have your familiar take the form of an Abomination, Celestial, Construct, or Fiend using the same restrictions as above.