Morph-flesh monstrosity

The morph-flesh monstrosity is a self-changing barbarian subclass with focus on morphing „natural“ weapons and in combat regeneration. This subclass is not designed to be used in any place close to societies as it will almost always be seen as monstrous and abominable due to its very nature of morphing, consuming and growing flesh. Also it might be a bit broken. Definitely for the most edgy of barbarians. Where these abilities come from is up to the player and DM, be it radiation, a failed arcane or scientific experiment, gen-modified corn or whatever reason you come up with.

Morph flesh

At level 3, as a bonus action, you can morph your arms into natural weapons that deal 1d6 (1d8 at 6th, 1d12 at 12th and 3d6 at 18th) + non-magical damage, depending on which morph is used of the three available.

Claws

Morph your hands into claws that deal slicing damage. These arms are capable of interacting with items that require fingers.

Chitinous Lance

Morph your dominant arm into a chitinous lance that deals piercing damage and the other into a extendable tendril arm. These arms are not able to interact with items or anything that requires fingers. The lance arm has the reach property.

Metal fists

Morph your hands into hulking metal fists that deal bludgeoning damage and can block attacks, therefore increasing your Ac by 2. These arms are not able to interact with anything that requires fingers.

Furious feeding

When raging, feed from the dead meat of your enemies and heal your wounds. Heal 1d4 (1d8 at 18th lvl) + your constitution modifier for the use of this ability. This uses a bonus action.

Advanced morphing

You have learned how to use new parts of your morphed weapons have gained the following benefits for each weapon:

Claw leap 

With the claws as your morphed weapon you can use a bonus action to take a leap up to 30ft to your target, ignoring entities of the sizes large or smaller in your way.

Tendril abduction

With the lance as your morphed weapon you can use a bonus action to use your tendril arm to pull a creature within 30ft of the sizes medium and smaller into your melee attack range, or pull yourself into melee attack range to a creature of the sizes large and bigger. Creatures that are pulled to you can resist by accomplishing a strength saving throw of the dc 10 + your strength modifier + your proficiency bonus.

Weapon catching

With the metal fists as your morphed weapon you can use a bonus action to prepare yourself for the next enemy melee weapon attack. If you are attacked by a melee weapon attack in the time space between this and your next turn, you can choose to catch the melee weapon with your metal fists. If the enemy has rolled above your AC on their attack roll, you can negate the damage, but you have to declare catching the weapon before you know the damage. If the enemy rolled under your AC, you can try to disarm your opponent by grabbing their weapon and rolling opposing strength checks. Only one of these actions can be performed, after one of these actions has been performed your character goes back to being normal. If disarming natural weapons is possible is up to your DM and has to be decided for every creature individually. (Blocking an adult dragons bite with your fists is insane enough, it should not have to worry about its jaw being broken by a single strike as well. Even tough some angry guy breaking a dragons jaw with his fists alone would be funny, that is why it is up to the DM.)

Freakish regrowth

Regrowth

On a long rest, you can pick one body part that is missing from your body to regrow.

Stem-cell farming

You can use 3 hours of downtime to grow 3 chicken-fillet sized meat parts out of your body that can be given to other party members as a healing item. These are placed like a band aid over the wound to turn into the missing tissue. The healing received is equal to 1d12 + your constitution modifier and it can cause body parts, smaller or equal in size to the meat parts, that have been lost to regrow.

This alone can not be used to reanimate a very recently deceased corpse, but if the DM allows it, can be used to replenish critical parts of the body to make the creature revivable through electric currents. 

Eating the meat parts does not result in the healing effect.

Regeneration leeching

You steal the nutrients from fast healing creatures regeneration and use them for your benefit. Heal for half the amount of health a regenerating creature would heal after you hit it with your morphed arms and stop its regeneration in the next turn. Also stops regeneration based damage resistances and immunities (Because screw werewolves).