Hmm . . . it occurs to me . . . a lot of those races that you won't use because of they dynamic model issue . . . such a lizardfolk (to make those lizard-feminists happy), draconians, lupins, etc. could use a dynamic model with a helm for a head. I know calibans are allowed to play as having a helm for their heads, and things like tails and wings could be added on by DM request . . .