Before you even think about creating a denizen read the Denizens Intro. Info about all the catagories can be found there. This form is designed to be very easy to fill out. The only area which will require a little effort on your part is the Appearance portion. This should be as detailed as possible. Lack of effort in this area will earn your denizen a trip to the trash bin.
Keep in mind that super baddies don't compose the bulk of the denizens of the universe. I would like players to submit medium strength and even weak denizens. Right now everyone is very low level. Super baddies are all but useless to the GM's until there are characters strong enough to fight them. Special abilities, attacks, and immunities should be rare. Few denizens will possess more than a handful of these. If your going to make something strong thats fine. If you make something all but invincible it will be deleted.
Think about your denizen a little before you start filling stuff out. Things should make sense. If you create a denizen that lives in an arctic climate it probably isn't going to be immune to fire. If it is immune to fire you probably need to list an explaination for this.
Each accepted denizen will earn your character $20/20.