Draconic tail

A racial feat for dragonborns.

Like your draconic ancestry, you grew a long muscular tale to aid in balance, flight, and swimming. It is not prehensile enough to act as an extra limb, however it helps with movement and defending oneself.

The tail allows you extra swimming speed and control in combat.

You gain an extra 10 feet of swimming speed as well as advantage on athletics checks made for swimming.

In combat it can act as a natural weapon, doing 1d6 slashing damage and improves shoving in combat. If you are doing the shove attack it functions like a generic shove, except they use Constitution or Acrobatics to defend against the users Strength. If you succeed on the shove you roll the damage of 1d4 bludgeoning damage. You don't have to choose 1 or the other when gaining this feat. You have freedom of choice given the situation which attack you make with it.

It can benefit from buffs that make natural weapons have a magic bonus from certain items or class feats like a monks ability to make his fists magical.