It seems that each of them have taken on attributes of a particular animal. As far as I can figure, here's how it breaks down for the ones I've gotten so far and the ones I've seen:
- Bulkhead - Snake
- Soundwave - Parrot (fits his function for certain since he only plays back what he hears, just like parrots)
- Bumblebee - Porcupine
- Starscream - either some sort of Fish or a Scorpion (I'm leaning towards the latter due to his black 'tail' that sticks up behind his back in bot mode, kinda like Beast Wars Scorponok)
- Wheeljack - jury's still out on him, but I'm definitely thinking some kind of bird of prey like maybe an Eagle or Hawk
- Smokescreen - not sure if he counts since he just has bits of clip-on armor, but if I had to guess, I'd say spider, especially due to his weapon
- Arcee - don't have her yet, but definitely a Bat
- Dreadwing - don't have him yet, but obviously a bird of prey, just like Wheeljack
- Ratchet - everybody knows he's a Dinosaur
- Knockout - don't have him yet, but he is an Alligator for certain
- Shockwave - don't have him either, but whatever it is, I think it's Alien (and very very creeeeeepy
)
- Optimus Prime - still not sure as he's not quite as 'Beast Hunter-y' as the deluxes and seems much more inspired by inorganic things...like Transformers Cybertron/Galaxy Force
After realizing this, the alt modes and changes in appearance and color didn't bother me nearly so much. It's an odd hybrid concept, but now that I feel I understand it a bit better, it's actually kinda cool and hearkens back to old toylines like Jayce the Wheeled Warriors and Visionaries and weird stuff like that from the 80's, things that as a kid I could really get into so seeing these new toys gave me a very different (and not so 'Transformers-y') kind of nostalgia kick that I'm enjoying quite a lot.