Meshentere
Meshentere, often called shentere for short, are rare. Very few and far between. They can take just about any form, though they tend to remain in each form for a while, as the act of changing shape takes a lot out of them.
Bonuses to Constitution and Wisdom, Charisma flaw.
Give this an ancestry with abilities and feats, maybe. Need to look at the balance of existing ancestries for this, see how possible it is to allow for THE FANTASY while still being balanced.
https://docs.google.com/spreadsheets/d/1d6iC8OzSGWI0DgIiqf69FxdoKeuzvb3539GA6QYwmqU/edit#gid=0
https://paizo.com/threads/rzs430i2?Basic-Ancestry-Guide
Around four or five 1st level feats and at least two 5th, two 9th, and two 13th level feats. - This is the MINIMUM. Dwarves have 55 feats, elves have 42, gnomes have 39, and goblins have 42. You can probably snag some feats from other ancestries and do some simple things, but fill that list OUT, give them CHOICE, shapeshifters are all about fluidity at the end of the day.
Changing shape inflicts Fatigued, takes 1 hour, and they must consume a full day’s rations to do so. Limitations on what types of forms can be taken, improved through ancestry feats.
Meshentere have an allergy to unfiltered arcane magic, maybe?