Path of the Mutant (by laserllama)

Through the study of alchemy and dark transmutation magic, some reclusive warriors have discovered a way to chemically alter their physical forms. By combining powerful alchemical reagents and the pure unbridled energy of their rage, they can trigger massive physiological changes within themselves. Barbarians who follow this Path of the Mutant are on a quest to evolve their bodies into the ultimate killing machine.

Aberrant Alchemy

Your research into the more sinister side of alchemy has paid off. When you adopt this Primal Path at 3rd level, you gain proficiency with alchemist's supplies and in the Nature skill.

In addition, you learn three Mutations of your choice. At the end of a long rest, so long as you have access to alchemist's supplies, you can replace one of your Mutations with another Mutation of your choice for which you meet the prerequisites.

Aberrant Sight

You sprout unnatural eye stalks or manifest additional eyes. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. If you already have darkvision its range increases by 60 feet.

In addition, you have advantage on Wisdom (Perception) checks that rely on your sense of sight.

Acidic Bile

You can spew a corrosive substance forth from your mouth. You learn the acid splash cantrip, using Constitution as your spellcasting modifier. You can cast this cantrip while raging, and when you do, it deals additional damage equal to your Constitution modifier (minimum of +1).

Alchemical Resistance

Your experiments grant you resistance to the elements. When you manifest this Mutation choose acid, cold, fire, poison, or lightning, and you gain resistance to that type of damage.

Aquatic Adaptation

You sprout unnatural gills or your skin becomes permeable and amphibious. You gain a swimming speed equal to your movement speed, and you can breathe both air and water.

Corrosive Secretions

Your body secretes a corrosive acid that burns your foes. When you are hit by an attack and the attacker is within 30 feet of you, you can use your reaction to deal acid damage 
to the attacker equal to 1d6 + your Constitution modifier.

Deviant Glide

You grow bat or fish-like skin flaps that you use to glide. When you fall and are not incapacitated, you can subtract up to 100 feet from your fall when calculating fall damage, and you can move horizontally 2 feet for every 1 foot you fall.

Enhanced Movement

Your legs grow unnaturally thick or powerful. Your movement speed increases by a number of feet equal to 5 times your Constitution modifier (minimum of 5 feet), and you can add your Constitution modifier (minimum of +1) to the distance of any long jump or high jump you make.

Grappling Appendages

You grow two appendages alongside your arms that resemble tentacles or large pincers. They are natural weapons, which deal 1d6 bludgeoning damage on hit. After you hit a creature with a melee attack, you can attempt to grapple them with these appendages as a bonus action. These appendages are not dexterous enough to use weapons or specialized tools.

Oozing Form

Your body becomes slimy and pliable. As a bonus action, you can automatically escape a grapple or nonmagical restraints. Also, your body, along with any equipment you are wearing or carrying, can squeeze through spaces as narrow as 1 inch.

Perverted Flight

You sprout a pair of unnatural leathery or insectoid wings. You gain a flying speed equal to your movement speed.

Synthetic Carpage

Your skin hardens resembling that of a hulking insectoid or terrible reptilian creature. You gain a bonus to your Armor Class equal to half your proficiency bonus (rounded down).

Toxic Vitality

Your body mends itself as you fight. At the start of your turns, while raging, you gain temporary hit points equal to your Constitution modifier (minimum of 1 temporary hit point).

Unnatural Physicality

Your muscles and veins engorge with toxic chemicals that grant you unnatural power and maneuverability. You gain a bonus to any Strength (Athletics) and Dexterity (Acrobatics) checks equal to your Constitution modifier (minimum of +1).

Viscous Grip

Your hands and feet secrete a sticky substance. You gain a climbing speed equal to your movement speed, and you can climb difficult surfaces, including upside down on ceilings, without making an ability check.

Manifest Forms

The energy of your rage triggers an alchemical reaction with your blood. Beginning at 3rd level, when you enter your rage, you manifest a number of Mutations you know of your choice equal to your Constitution modifier (minimum of 1 Mutation). These Mutations last until the end of your current rage.

Enduring Mutation

Your advances in the dark alchemy of mutation have evolved. Starting at 6th level, at the end of a long rest, you choose one Mutation you know. Until the end of your next long rest, you always have that Mutation manifested, even when not raging. When you enter a rage, this Mutation counts against the total number of Mutations you can manifest for that rage.

In addition, you learn two more Mutations of your choice.

Toxic Vigor

The toxic elixirs and potions you have consumed to further your research have hardened your body against all but the most noxious substances. At 6th level, you gain resistance to both acid and poison damage, and you are immune to the poisoned condition.

Noxious Strike

You can weaponize the toxins in your blood. Beginning at 10th level, when you hit a creature with a melee attack, you can force it to make a Constitution saving throw to resist being infected by the wild toxins that flow in you. DC equal to 8 + your proficiency bonus + your Constitution modifier. On a failed save, roll a d6, and the target immediately suffers the corresponding condition from the table below.

D6     Effect

1        blinded

2        charmed

3        stunned

4        frightened

5        paralyzed

6        poisoned

    This effect lasts for 1 minute. The creature repeats this saving throw at the end of each of its turns, ending the effect on a success. A creature that succeeds on their saving throw is immune to this effect for the next 24 hours.

You can use this feature a number of times equal to your Constitution modifier (minimum of once), and you regain all expended uses when you finish a long rest.

In addition, you learn one additional Mutation.

Rapid Mutation

Upon reaching 14th level you have gained mastery over your body and its mutability and you can change your form at will. While raging, you can use a bonus action to end one of your Mutations, replacing it with another Mutation that you know.

You can use this ability a number of times equal to your Constitution modifier (minimum of once), and you regain all expended uses when you finish a long rest.

In addition, you learn one final Mutation of your choice.