There is a Legacy version
here.
Dragon Transformation [one-action] Feat 16Barbarian Concentrate Polymorph Primal Rage Source Player Core 2 pg. 84Frequency once per 10 minutes
Prerequisites Dragon's Rage Wings
You transform into a ferocious Large dragon, gaining the effects of 6th-rank
dragon form except that you use your own AC and attack modifier, you apply your extra damage from
Rage, and the Dragon Breath action uses your class DC. Add the temporary Hit Points from
dragon form to any you already have from entering a rage (or any other action with the
rage trait). The action to Dismiss the transformation gains the
rage trait.
At 18th level, you gain a +20-foot status bonus to your fly Speed, your damage bonus with dragon Strikes increases to +12, and you gain a +14 status bonus to your Dragon Breath damage.
Traits
Concentrate: An action with this trait requires a degree of mental concentration and discipline.
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.
Rage: You must be raging to use abilities with the rage trait, and they end automatically when you stop raging.