Sting ray transformer! Called it! I would be blue & gray and be a Stig ray in animal form and an aquatic robot. My name would be Hydrasting. I know, It's corny, but meh.
I would be a manta ray, but what purpose would that serve as a robot?
Alright, I just saw the movie so let's put more thought into this.
I would be named Shia LaBeouf, and I would transform into him so that I could make out with Megan Fox ;D
Lol, ok let's pick something for real.
I'd be named...Chord (it's my name for halo and such) and I'd transform into a Harrier AV-8B jet. Vertical take offs, awesome. That was filmed at the airshow I just volunteered at, so I got to see that up close. Awesome.