You are allowed to take a subclass feature, of a class you have a level in as a Feat, but you must have a level in the class that is of the same, or higher level as the feat you take.

For Example: A 4th level fighter may take a 3rd level Fighter subclass Feature as a Feat, but not a 7th level feature

Ability Score Increase. Increase your Strength or Dexterity by 1, to a maximum of 20.

Climb Speed. You gain a Climb Speed equal to your Speed.

Swimmer. You gain a SwimSpeed equal to your Speed.

Hop Up. When you have the Prone condition, you can right yourself with only 5 feet of movement.

Jumping. You can make a running Long or High Jump after moving only 5 feet.

Punch and Grab: When you make an unarmed attack, you can deal damage and grapple a creature. You gain this benefit once per turn.

Fast Wrestler: You do not expend extra movement to move a creature grappled by you if that creature is your size or smaller..

 

Body Slam: While you have a creature grappled, you can perform a throw instead of a shove. When performed this way, you can throw a creature into any adjacent square of you, dealing 2(1d4) + your Strength or Dexterity modifier as Bludgeoning damage.

 

Sleeperhold: While you have a creature restrained via a grapple, you can use your action to attempt to start choking it. To choke the creature you make a Strength(Athletics) check at disadvantage opposed by the creature's a Strength(Athletics) or Dexterity(Acrobatics) check, if you succeed the creature starts choking until the grapple ends.

A choking creature is unable to breathe or hold its breath and cannot speak or perform verbal spell components. If a creature is reduced to 0 hitpoints as a result of choking, it will be unconscious and stable.

Ability Score Increase: Increase your Strength or Dexterity score by 1, to a maximum of 20.

Bonus Attack: On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.

 

Critical Mass: When you score a critical hit with a heavy weapon that you are proficient with, you deal maximum weapon damage prior to rolling for critical damage.

(A Critical for a greataxe would deal 12 + 1d12 damage instead of 2d12)

Ability Score Increase. Increase your Dexterity or Constitution by 1, to a maximum of 20.

Speed Increase. Your Speed increases by 10 feet.

Dash over Difficult Terrain. When you take the Dash action on your turn, Difficult Terrain doesn't cost you extra movement for the rest of that turn.

Agile Movement. Opportunity Attacks have Disadvantage against you. When you make a melee attack against a creature, you don't provoke opportunity attacks from that creature for the rest of the turn, whether you hit or not.

Ability Score Increase. Increase your Dexterity score by 1, to a maximum of 20.

Bypass Cover. Your ranged attacks with weapons ignore Half Cover and Three-Quarters Cover.

Firing in Melee. Being within 5 feet of an enemy doesn't impose Disadvantage on your attack rolls with Ranged weapons.

Long Shots. Attacking at long range doesn't impose Disadvantage on your attack rolls with Ranged weapons.

Ability Score Increase. Increase your Intelligence, Wisdom, or Charisma by 1, to a maximum of 20.

Bypass Cover. Your attack rolls for spells ignore Half Cover and Three-Quarters Cover.

Casting in Melee. Being within 5 feet of an enemy doesn't impose Disadvantage on your attack rolls with spells.

Increased Range. When you cast a spell that requires you to make an attack roll, the spell's range is doubled.

 

Addtional Cantrip: You learn one cantrip that requires an attack roll. Choose the cantrip from the bard, cleric, druid, sorcerer, warlock, or wizard spell list. Your spellcasting ability for this cantrip depends on the spell list you chose from: Charisma for bard, sorcerer, or warlock; Wisdom for cleric or druid; or Intelligence for wizard.