Steed Master (5e Feat)
From D&D Wiki
Prerequisites: Proficiency in Animal Handling
You learn the Find Greater Steed spell. You can cast it at its lowest level without expending a spell slot. You regain the ability to do so after a long rest.
Creatures that you are mounted on can take the Attack action, making only one attack per turn. If it does not have an attack, it gains an attack using its Strength modifier + its proficiency bonus for the attack roll and dealing 1d4 + its Strength modifier.