Okay, this is an older one. It takes place in another dimension that is identical to ours except that primates evolve much faster *that includes us silly :3*. Well because of different beliefs and stuff we evolved into three different kinds of creatures.

Angels *I know, how unoriginal*:
-Got wings
-Nails grow longer and faster
-Wings made from feathers and are kept together by seperate bones *each singular feather can be controlled*
-Newborns don't aquire wings until they become 13
-13-18 year olds wingspan is 1-3 feet *only ones with the greatest skill can fly*
-wingspan grows MUCH larger at eighteen *grow up to 6 feet*
-Angels are very fast and agile but have a humans strength.
-Angels make up about 7% of the population
-An angels height vary's from around 5' 10" to 8' 9"
-Angels learn a little faster than humans
-Angels are the positive side of the spectrum
-Angels don't trust any other kind at all
-Angels love pie, I'm not even kidding
-Angels lose energy and eventually die when in the darkness for too long
-Angels don't eat or drink *They live completely off of solar energy *not artificial light**
-Angels don't have testoserone or estrogen
-Angels have small genitals *Other creatures pick on them for that*
-Angels support christianity *duh*
-Angels often get picked on by humans in schools but are too nice to react
-Angels have above average hand to eye coordination
-Angels lack in communication skills
-Everything else about them is human like
-Angels can only get pregnant by their soul mate.
-They can sense their soul mate through a sixth sense
-The angels main color is blue

So that kid in school that is too afraid to prove hinself but DOES have the skills and that is picked on often is probably an angel.

Demons *pretty predictable huh?*:
-Got wings
-Nails and teeth grow faster than an angels
-Wings are like a dragons *just not as huge silly XD*
-Newborns have very small wings *only a few inches*
-Wings go away at twelve and grow inside the body
-Wings reappear in the twenties
-Wings bust out of the body and spray a goopy, clear-ish liquid *looks almost like infected puss* all over the place *the pouch that the wings were contained in contained this liquid to disallow stress upon the rest of the body.
-Wings are HUGE *The wingspan is about twenty feet*
-Demons are strong but slow *about the speed of a fat guy*. Don't defy their intelligence though. Many are smarter than angels.
-Demon make up about 18% of the population
-Demons range from 6' 2" to 14' 0".
-Demons are obviously the negative side of the spectrum
-Demons are fine with everything except angels
-Demons love alcohol.
-Demons actually like the light even though they see very well in darkness
-Demons have twice as much testosterone and twice as much estrogen than the average human.
-Demons have above average genitals
-Demons are usually atheist although some differ
-Demons pick on people but not insanely like bullies
-Demons think violence is the way to shut someone up.
-Demons love sex with everyone except the new kind that has just shown up in the world
-Demons can't get pregnant with anyone except demons
-Demons stay pregnant for two months *that's it XD*
-Demons HATE getting pregnant
-Demons excel in communication
-Everything else is human like
-The demons main color is red

That kid that goes around dating everyone in your school is probably a demon.

Elementals:
-Don't have wings
-Nails grow smoother and more ovular than a humans
-They CAN fly *they manipulate the air around them to do this*
-They can manipulate the four elements obviously
-They usually excel at only one element but can still use the rest really well
-Elementals learn to use their powers at any age *including in the womb*
-Elementals can improve their abilities through rigorous training
-An elementals dominant power also depends on his/her attitude and horoscope
-The elementals are average in everything but are extremely intelligent to the point where most have telekinesis
-They take up about 2% of the population
-They range from 5' 4" to 6' 2"
-They are the intelligent side of the spectrum
-They treat everyone equally
-Elementals love sushi
-Elementals love twilight *not the book stupid XD*
-Elementals have average testosterone, but above average estrogen.
-They have above average genitals too
-They are usually pagan
-They are a bit insecure
-They try reasoning at first but won't hesitate to use violence
-They like sex more than humans but its not such a big deal
-They can get pregnant with humans and other elementals
-The babies that are born with humans still become normal elementals
-They are good when communicating but prefer to keep to their own selves
-Everything else is human like
-Their color is yellow

This kid is usually quite until you get to know them. They usually are superstitious though

The annihilators:
-No wings
-About the size of the left4dead tank
-Colossus like genitals
-Nearly undestroyable
-Can pick up the sears tower with arms
-Is killing everything
-There are only 20 in the whole world
-The rest is unkown

This is just some background information that your going to need to know :D. I'll post the rest some other time.

P.S. The picture is a left4dead tank.