[PF] Monsters with several forms

[Vanitas]

Do you guys know of any PF monster with several forms in the spirit of Final Fantasy bosses? I mean, monsters that could go One-Winged Angel (http://tvtropes.org/pmwiki/pmwiki.php/Main/OneWingedAngel) at the players' faces? More specifically, monsters that could do that and get an actual advantage out of transforming? I can't think of any.

[grarrrg]

One-Winged Angel (http://tvtropes.org/pmwiki/pmwiki.php/Main/OneWingedAngel)

YOU FOOL! You've doomed us all!
Why?
WHY!?
*breaks down sobbing*

[Crasical]

Contingent Polymorph/Shapechange, is the obvious way to set up a 'multi-form' battle. Hydra are sort of a similar thing, as they slowly evolve throughout the fight, getting new heads.

Different 'phases' of the fight are easier, a warrior-type enemy ditching his shield and starting to wield his weapon 2-handed for better power-attack bonuses or a wizard who only personally deigns to start targeting the party once his summons are dispatched are both fights with different phases.

[Vanitas]

Contingent Polymorph/Shapechange, is the obvious way to set up a 'multi-form' battle. Hydra are sort of a similar thing, as they slowly evolve throughout the fight, getting new heads.

Different 'phases' of the fight are easier, a warrior-type enemy ditching his shield and starting to wield his weapon 2-handed for better power-attack bonuses or a wizard who only personally deigns to start targeting the party once his summons are dispatched are both fights with different phases.

The problem for those is basically a lack of HP. 3.5 had Dragonform grant 150 temporary hit points, but there is no similar spell (that I know of) in PF