Upper_Krust
Legend
Hi CRGreathouse mate! 
'Easily'!?
Notwithstanding the design philosophy implications.
Any being that has class levels is (by definition) an individual.
How many monsters in the Monster Manual have class levels*...effectively none (except individual examples).
*Not counting intrinsic spellcasting levels.
You simply cannot design 'creatures/races' like that.
If a Seraphim is a titanic dragon with four heads and six wings, you can't just say its an Astral Deva with some Prestige Class Levels (even if those Prestige Classes made it dragon-like and granted multiple heads and extra sets of wings). Its a race, not a career.

CRGreathouse said:I think that "feat/class/prestige class/etc." can easily include divine/cosmic/omnific gifts, turning your comment right back around.
'Easily'!?

Notwithstanding the design philosophy implications.
Any being that has class levels is (by definition) an individual.
How many monsters in the Monster Manual have class levels*...effectively none (except individual examples).
*Not counting intrinsic spellcasting levels.
You simply cannot design 'creatures/races' like that.
If a Seraphim is a titanic dragon with four heads and six wings, you can't just say its an Astral Deva with some Prestige Class Levels (even if those Prestige Classes made it dragon-like and granted multiple heads and extra sets of wings). Its a race, not a career.