Pit Beasts are fighters who embrace their savage side, which manifests as a bestial spirit suffusing them. While they may have to contain their wild side much of the time, on the battlefield they can unleash it to attack with overwhelming aggression, while simultaneously taking punishment and unyieldingly growing more ferocious as the stakes increase. Even when they've been knocked down, their urge to fight on can push them beyond the limits of their mortal body.

Claws That Catch

When you use your action surge feature, you can call upon your bestial spirit to manifest as a spectral natural weapon, such as a pair of claws, horns, fangs, or a spiked tail. This effect lasts for an hour, or until you become unconscious or dismiss it at will. Your unarmed strikes utilizing your natural weapon deal additional force damage, which increases as you gain levels in this class. You are considered proficient with this weapon.

When you choose this subclass at level 3, you decide what form your natural weapon takes. The form is represented by two choices: Whether your unarmed strikes are modified to deal bludgeoning, piercing, or slashing damage, and which weapon mastery property your weapon grants you access to. 

The bonus force damage dealt by your natural weapon is 1d4, increasing when you reach levels 5 (2d4), 11 (3d4), and 17 (4d4). 

Primal Perks

The beast within shows itself in increased fortitude, and a minor animalistic augmentation to your appearance. You gain advantage on constitution saving throws, and proficiency in either athletics, intimidation, perception, survival, or stealth from your animalistic feature.

Athletics Proficiency

Your bestial characteristic grants you proficiency in Athletics.

Intimidation Proficiency

Your bestial characteristic grants you proficiency in Intimidation. 

Perception Proficiency

Your bestial characteristic grants you proficiency in Perception. 

Stealth Proficiency

Your bestial characteristic grants you proficiency in Stealth.

Survival Proficiency

Your bestial characteristic grants you proficiency in Survival. 

Savage Spirit

While below half of your maximum hit points, or while unleashed, gain advantage on weapon attacks made with your natural weapon, and add your Constitution modifier to the bonus force damage dealt by their strikes.

Killer Comeback

While you would be reduced to 0 hit points, you can expend a use of your second wind feature as a reaction, regaining the hit points and remaining conscious and on your feet. When doing so, your natural weapon from your Claws That Catch feature manifests until the end of combat.

Pit Grit

Your second wind feature is now able to be used while incapacitated. When you use your second wind feature, you may choose any number of the dice you would roll for healing, instead removing a condition from yourself for each die not used for healing. The conditions able to be removed with this feature are: Blinded, Charmed, Deafened, Frightened, Incapacitated, Paralyzed, Poisoned, and Stunned.

Unleash The Beast

Killer Comeback is enhanced. When you use it, you can instead regain all missing hit points, becoming unleashed until you fall unconscious. While unleashed, you take 1d6 +1 necrotic damage at the end of your turn, which cannot be reduced in any way. At the end of your next turn, this increases to 2d6 +2, then 3d6 +3, and so on until you reach 0 hit points. While unleashed, landing an attack with your Claws That Catch weapon restores 1d6 hit points to you, and you gain the bonus of Savage Spirit even if you're above half your total hit points. You also take on a more bestial appearance. Once you fall unconscious, you cannot Unleash The Beast again until you complete a long rest.