Strength of Eight Legions Feat 17Polymorph Primal Yaksha Source Tian Xia Character Guide pg. 81
You meditate for 24 hours in a one-time ceremony within a forest or cave; after your seclusion, your frame and limbs swell with warlike might to enact your vows. You permanently gain the effects of
enlarge, and your maximum Hit Points increase by your level. The ceremony transforms most of your gear to the appropriate size for your new body (though powerful items like artifacts or items strongly tied to their original size can’t transform, at the GM’s discretion).
Traits
Polymorph: These effects transform the target into a new form. A target can't be under the effect of more than one polymorph effect at a time. If it comes under the effect of a second polymorph effect, the second polymorph effect attempts to counteract the first. If it succeeds, it takes effect, and if it fails, the spell has no effect on that target. Any Strikes specifically granted by a polymorph effect are magical. Unless otherwise stated, polymorph spells don't allow the target to take on the appearance of a specific individual creature, but rather just a generic creature of a general type or ancestry.
If you take on a battle form with a polymorph spell, the special statistics can be adjusted only by circumstance bonuses, status bonuses, and penalties. Unless otherwise noted, the battle form prevents you from casting spells, speaking, and using most manipulate actions that require hands. (If there's doubt about whether you can use an action, the GM decides.) Your gear is absorbed into you; the constant abilities of your gear still function, but you can't activate any items. If a polymorph effect causes you to increase in size, you must have space to expand into or the effect is disrupted.
Primal: This magic comes from the primal tradition, connecting to the natural world and instinct. Anything with this trait is magical.
A creature with this trait is primarily constituted of or has a strong connection to primal magic.
Yaksha: Divine spirits who emigrated to Golarion from the first world.