Hehe, sorry about that ;) *tempts you some more*
The pets have stats to raise, some by giving them items, some they raise from quests and games (more or less happens in the background if you use the site). They have different stages they unlock, but you can choose which one it uses and change that around as often as you like.
There are different types of pets and each comes in different colour variations.
You can only have one to raise at a time, once you max that you can choose another one (or you can buy premium items to have more, but I kind of like this feeling of you raise this one pet now, I would be stressed out by raising multiple at a time and I feel like I have a stronger bond to it this way).
Examples of inital stages: