Highway Rider.

Stalking the backroads, the Highway Rider strikes fear into the heart of every traveler and penny-pinching merchant. They run down their prize astride a swift and loyal steed–and then make a quick getaway.

Level 3 Feature:

Hair Trigger.

Starting at 3rd level, when you roll for initiative, you can immediately use your reaction to take one of the following actions:
-Make one weapon attack with advantage
-Move your speed, or your mount's speed, without provoking opportunity attacks
-Take the Dodge action
-Interact with an object or use an item

Trusty Mount.

At 3rd level, you can cast the Find Steed spell. When you do, its creature type remains beast rather than changing to your choice of celestial, fey, or fiend. Once you cast this spell using this feature, you can't do so again until you finish a long rest.

Ride them Down.

Also at 3rd level, you gain an additional way to use your Sneak Attack: you don't need advantage on the attack roll to use your Sneak Attack against a creature if you or your mount moved at least 30 feet this turn, and you don't have disadvantage on the attack roll. All the other rules for Sneak Attack still apply.

Level 9 Feature:

Horse Lord.

At 9th level, you can spend a minute grooming and caring for your mount, at the end of which time it gains temporary hit points equal to twice your level in this class.
In addition, your cunning extends to your steed. While you are controlling a mount, it can spend a bonus action on its turn to take the Dash, Disengage, or Dodge action.

Level 13 Feature:

True Grit.

At 13th level, you gain proficiency in Constitution saving throws. In addition, when you are subjected to an effect that allows you to make a Constitution saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.

Level 17 Feature:

Desperado.

Starting at 17th level, when you are reduced to 0 hit points, you can use your reaction to take one of the actions listed in your Hair Trigger feature immediately before you fall unconscious.