Pokemon fever

My sons have only recently gotten bitten by the Pokemon bug. While there have been many times I thought I would scream if I heard the word again, it has led to some fun, including making up our own Pokemon. I encourage him to make up his own, develop and draw them. Well, I got sucked into it, too.
This is my first attempt at creating a Pokemon - Sharkor!
I have been informed that this is obviously an "evolved" Pokemon, and apparently I need to come up with the first, unevolved state. I almost think I understand that, which scares me. I'm sure there will be more of these...