This is important.
What is the ultimate tail? We all know that fluffy tails hold a special place in all our hearts, but what of succubi/demon tails? Twintails? Dog tails? Cat tails? Cow tails? What about multiple tails, how many tails are too many, how many too few? Should this ultimate tail be hideable through magic or should they always stick out, or be (badly) hidden in her skirt. How big should it be? What about tail strength / agility, should it be able to lift heavy objects? What about tails made of Nipponese steel, folded 9000 times? What about tails on other tails? What about cute girls who are anthopomorphized tails of varying types doing tail things?
So many dire questions /a/. So many questions.
fox tail, always there, magic hiding said would be cool but seems like cheating, gotta love your girl for her tail all the time or not at all
Squirrel tail. So big and fluffy, it's made for hugging