Polearm Master

You gain the following benefits:

When you take the Attack action and att⁠ack with only a Glaive, Halberd, Quarterstaff, or spear, you can use a Bonus Action to make a melee att⁠ack with the opposite end of the weapon. This attac⁠k uses the same ability modifier as the primary Attack. The weapon’s damage die for this Attack is a d4, and the at⁠tack deals bludgeoning damage.
While you are wielding a Glaive, Halberd, pike, Quarterstaff, or spear, other Creatures provoke an opportunity Attack from you when they enter the reach you have with that weapon.