SHADOW Prince and Princess: These two people (Marz and Venus FalconHeart) are the reason why the SHADOWS attack you. They are the only ones allowed to send shadows to attack people and they are the only SHADOWS you may NEVER GO UP AGAINST. THEY ARE UNBEATABLE!!! So yeah dont try and fight them. They take on the form of white haired cat anthromorphs and will trick you into a false sense of security before sending SHADOWS to destroy you later on. (for further information on these two look at their profiles.)
http://adollloversparadise.deviantart.com/gallery/39742267 (scroll down the page tillyou find them its pretty obvious)

Alpha: These SHADOWS tend to have quite the nasty disposition. They can be told apart from the rest by their abilities and eye color. The Alphas are the only Shadows whom can take on the shadow of anything on Gaia (not to be confused with the dragon girl) but when they their eyes are white so if you see a person/object/plant whose shadow has white eyes RUN! DO NOT ATTEMPT TO FIGHT AN ALPHA ALONE IF YOU VALUE YOUR LIFE!!! Alphas are only to be taken on by a group of four plus. The reason for this is simply because I care and want all my players to be safe... Also Alphas will break apart their bodies and bombard you relentlessly from all sides. Alphas tend to take on Human forms. They also tend to buddy up with other Alphas to take over whole kingdoms. Alphas take over kingdoms so that they might breed with the women and consume their resources. (Although, if you need to attack or be attacked by an alpha for a specific purpose that is fine.)
http://browse.deviantart.com/?qh=§ion=&q=shadow+creatures#/d2wsyr0

Beta: Betas are just as nasty as alphas but not nearly as powerful these guys can take the shadows of Mountains and clouds and people. They can also like alphas be identified by a specific eye color and that is Orange. Gammas can only be taken out by a group of four.

Gamma: These SHADOWS can put up pretty nasty fight if encountered. They can be identified by Green eyes. They will take on the shadows of animals. They can only be taken out by a group of three.
http://girz94.deviantart.com/favourites/41054189#/d14r5sx

Delta: Not too much of a threat unless provoked. They can take on the shadows of and plants. They mainly keep to themselves they don’t bother with humans, Just animals. But if you do happen to encounter them make sure you have a buddy with you because they will defend themselves and one man alone isn’t enough. The reason being is because deltas are smart and tricky they tend to split themselves in half and attack both the front and the back. These SHADOWS have blue eyes.

Epsilon: Honestly a fight with an epsilon is sad. Just a few good punches and about two minutes later its dead. You can handle these all by your lonesome. These SHADOWS have pink eyes. They tend to take on the form of bugs.

Omega: Now these ones can be hard to kill simply because they gang up on you. If you encounter one alone, one good punch to its face and its gone baby. But I’d advise killing it quick because these little guys will call for backup and before you know it you’ve got a whole hole of them chasing you down and tiring you out. These SHADOWS have red eyes.
http://browse.deviantart.com/?qh=§ion=&q=shadow+blob#/d3htacf