I'd go with an Artificer archetype, with proficient with Herbalism and Leather working tools. Artificers already have a bunch of shape altering spells (disguise self, false life, alter self etc)
Create new Infusions that are taking the skin and soul of creatures to infuse your stuff.
At 3rd level:
- Prof with herbalism kit and leather working tools.
- Class spells:
1- Goodberry, Fog Cloud
2- Spiritual Weapon, Phantasmal Force
3- Aura of Vitality, Speak with death
4- Deathward, Polymorph
5- Commune with nature, Danse macabre
Soulmeld: Oncer per short rest, take the form of monstruosities of CR 1 or lower (increases the same as moon druid) for a number of minutes.
At 5th level:
- Attack from Souldmeld count as magical
Healing Herbs: During a short rest, people spending HD gains an extra 1d6 hit points
At 9th level:
Poultices Maker: you can create special herbal poultices that have healing power comparable to some potions. You can spend 1 hour gathering herbs and preparing herbal poultices using treated bandages to create a number of such poultices equal to your Wisdom modifier (minimum 1). You can carry a number of poultices at one time equal to your Int modifier (minimum 1). The poultices you create cannot be applied by anyone but you. After 24 hours, any poultices that you have not used lose their potency.
If you spend 1 minute applying one of your poultices to a wounded humanoid creature, thereby expending its use, that creature regains 1d6 hit points for every two artificers levels you have (rounded up).
at 15th level:
Master Skinwalker: Can use Soulmeld a number of time per shor rest equal to Int mod.
New Infusion
Skin of the Shark: Gain the Blood Frenzy trait
Skin of the Gorgon: gain a acid breath
Pelt of the Displacer Beast: can teleport 10 ft then speed fall to 0 ft for the rest of the turn.
Troll Bark: gain regen 1 when under half hp.
etc