So, I ended up picking this pet out of the three:
When I examined at the options, this one caught my eye.. Then the slick, graceful, watery dragon seemed interesting to me, and after that the spiny, green dragon.
It was so difficult to choose, and I'm not sure why. But I looked back to the time I first saw the pets, and that's when I realized the lava dragon was for me.
I've named him Fate. If I had more CS dollars, I would have bought the whole set. Unfortunately, that's not how I live. :P The watery one could be named Slip, and the green, prickly one could be Spino.
Anyway, even deciding between virtual animals is tough!