Polymorph Variant Appearance

[LastOblivion]

I'm trying to figure out if there is any means to alter only the appearance of polymorphed/metamorphosed forms by more than just simple physical changes. Ideally something that can pull of some radical changes without altering the effect of the spell.
Such as polymorphing into a troll but having the appearance of a character inside of a transparent troll form. Or polymorphing into an ogre mage with the ogre mage's size and vital statics but an appearance being a hybrid between that characters and the ogre.
I know you can alter the appearance of spells slightly without changing the effect already, such as making your fireballs blue. But I don't think i can apply that to shape changing spells.

[ExLibrisMortis]

Hmm. I think that might fall within the usual limits of refluffing. You're giving up a slight amount of power (don't need true seeing to detect true form), with only a small advantage (can be recognized). I'd allow it.

Mechanically, you can prepare a polymorph with Invisible Spell applied. That should hide the result of the spell, either turning you invisible, or making you look like your base form.