Path of the Pugilist

If you ever find yourself in a barfight with a pugilist, I hope you have a couple clerics handy. A pugilist will use their superior strength to beat down their foes unrelentingly. They will never flinch, and never sway. The more they fight, the harder they fight. They know exactly how to use their body weight, and their enemy's, to their advantage. When a monk fights, it's like watching a choreographed performance, when a pugilist fights, it's like watching a bull trample a halfling. A pugilist will come out of every fight either feeling better than before, or dead.

Hard hitter

Starting when you choose this path at 3rd level, when you rage, you can you can make a number of extra attacks when you take the attack action so long as they are made with your fists, or part of your body. The amount of extra attacks you can make is equal to your bonus rage damage. Reckless attack will benefit unarmed attacks. If you choose to reckless attack, you can also choose not to attack extra times, and instead do an extra d4 damage on your reckless attack for every attack you choose not to take. When you enter rage, heal yourself for an amount equal to your constitution modifier.

Immovable

Beginning at 6th level, you can’t be moved against your will by anything large or smaller, and have advantage against being moved by anything huge or larger. Also, you can add your constitution modifier to any athletics check you make, and any save to avoid being restrained. You can choose to add your constitution modifier to your ac instead of dexterity while wearing armor, and add up to +3 to your ac while wearing medium armor if you use your constitution. If you are wearing heavy armor, add your constitution modifier to your ac (maximum +2). When you kill an enemy while raging, heal yourself an amount equal to your constitution modifier. You cannot benefit from any of these features while wielding a weapon or shield. This feature does not grant proficiency with heavy armor.

Furious Punishment

Beginning at 10th level, you can use your enemy's attacks against them. If an enemy hits you with a melee attack, your next attack against them before the end of your next turn has advantage. If you successfully hit with this attack, you gain temporary HP equal to your constitution modifier. So long as you have this temporary hp, you have resistance to all damage except psychic. If an enemy misses you with a melee attack, you can use your reaction to attempt to grapple them with advantage, attempt to disarm them (contested str or dex), or use their momentum to throw them 10 feet behind you, knocking them prone if they fail a dexterity save with dc equal to 10 + your athletics modifier. If the enemy critical failed on the attack that missed you, they automatically fail the save for whatever you do. 

Brute force

Starting at 14th level, anytime you throw an improvised weapon, or any weapon that doesn't have the thrown property, the damage is doubled for that attack. Whenever you make an attack against a creature that is grappled by someone other than you, the attack has advantage and you can double your strength modifier for the damage. Any time an enemy attempts to grapple you and fails, you can use your reaction to throw your body weight into a special attack against them. This attack does damage equal to a d6 + your strength and constitution modifiers, and knocks the target prone if it hits. Whenever you pin a grappled target, you also deal a d8 damage to them.