Beast Forms
One of the unique features of Project Gorgon is that is allows players to choose to play as an animal. The animal forms like Cow and Spider were originalle intended as curses, but they each have their own playstyles, so some players enjoy playing as animals full time.
General Characterisation
Cow and Deer are both built as Tanks, Cow as more of your traditional tank archetype, while Deer can be considered an Off-Tank. With Cow your Tankiness/Tank-like Abilities come inherently from your skills. While with Deer, your tank-like abilities come from having the right mods on your gear.
Spiders would be similar to your dps/assassin types most of their skill is set on using Infinite Legs, or Poison abilities to quickly kill the enemy. The same can be said about Werewolves and Giant Bats, they're both known for their damage and their ability to keep the pressure on.
Pigs are your support build, they can solo decently, but they are better of in groups, as a healer or a buff build with use of Mudbath, Frenzy, Porcine Alertness.
Rabbits offer a stealthy playstyle.
Druids by themselves should NOT be classified as a Beast Form. However Druids are given spells that will allow them to assume certain beast appearances like Deer, Raven and Mallard.
Advantages
With Cows your advantages are you are a tank, so you have high survivability. Cows also have a nice sprint skill called Moo of Determination, and they have the ability to produce their own milk, which helps in crafting skills such as Cheesemaking, or Cooking. If you are a vegetarian Cow you have the ability to produce milk every 3 or 4 minutes, while if your a non-vegetarian you can only produce it every 5 minutes. Players can also milk other Player Cows every 15 minutes. Both are considerably better than waiting an hour to milk a specific cow.
Deers have the ability to jump faster/higher, they also have AoE Taunts, while Cow only has single target taunts. They have the ability also to summon another Deer Pet to help out in battle.
Spiders have the ability to use Insidious Illusion to talk to Animal Hating NPCs, it uses up a Moonstone. They also have the ability at lvl 50 to produce their own Spiderweb, which does help with crafting such as Tailoring, especially if they want to make their own Spider Carapace Armor.
Pigs have two sidebar abilities Terror Dash, which gives them a sprint bonus, and Truffle Sniff which allows them to sniff for mushrooms, I believe the higher the Truffle Sniff the higher lvl Mushroom you are likely to get, or the higher the chances you are of getting a mushroom.
Rabbits are the only Beast Form capable of using Ice Magic by equipping a special headgear item.
Giant Bats have the ability of Echolocation which allows them to see in the dark, such as dungeons (especially helpful with Claudia), and they do have the ability to Fly, they also have the ability to turn players into Bats, so be careful when facing them in PvP.
Wolves have the ability to switch in and out of wolf form(except during Full Moon, when they are stuck for 3 days), they also have specific Wolf-Altar/Wolf benefits, the altar can unlock higher lvl abilities, has the option of being a storage space, and by completing quests for the Altar you can get bonuses like Extra Armor, Power, Health, Damage Mitigation, Bonus Attack %, or a Sprint Speed bonus.
Disadvantages
Becoming a Werewolf / choosing for Lycanthropy is a PERMANENT CHOICE. It has some impactful consequences when doing that. It CANNOT be reversed.
One of the disadvantages of being an animal is Beast Speech. While typing in chat certain words can be changed to a sound-representation.
Example: a Cow might type "I'll wait for you near the Serbule well". But after pressing Enter the sentence may read as "I'll wait moo you near the Moooooo mooo". The words that will be replaced will be random.
Certain NPCs will not speak to you while you are an animal. Especially the ones in Serbule. But to counter that there are Animal NPCs in Animal Town which is in Sun Vale, who will speak to you, but only after you have been an Animal for 3 in game hours.
Another disadvantage is your inability to use skills that require hands, such as Sword, Fire/Ice Magic, Shield, and your inability to cut/gather wood, since skills that require the use of Hands do not work, since animals do not have hands (or thumbs).
Crafting Gear for Animal Forms
Observant players have noticed that it's hard to craft gear for animal-cursed players. There's only one gem that covers all animal curses, so you often craft Deer gear when you really want Spider gear, and so on.
In the next update (edit me), there will be a way to inscribe runes into those gems, so that you can attune the gem to one specific animal curse. You'll want to get your Sigil Scripting skill to level 25 to be able to use those techniques.
General tips regarding playing in an Animal Form
For general advice, avoid playing as an animal unless absolutely certain, and after you have explored zones such as Serbule and Etilbule as a human, and gotten at least some storage space, NPC favors done, and gotten used to the general feel of the game. Because starting off as an Animal can be hard or trying for a new player.
Be aware that the Animal Forms stack. If you are a cow, and drink a Deer Juice potion, you will appear to be a Deer. However you are also still cursed as a Cow. So after drinking an Un-Deer Juice, you will not be in human form, but will be a Cow again.
When just starting animal say something in nearby chat every 5 min or so. That way you will get exp in your Beast Speech, and won't bother people in global.
3-sylabe word of powers include ones that will grant you illusion, making you look like elf for 2 min. can be helpfull when talking to npcs
You definately should start working on favor in Animal Town asap, especialy if you are full time animal (eg - not wolf)
Jumper, Raul and Norbert in Sun Vale's Animal Town offers Storage only for players in animal form.
Seek out special NPC's
There are unique opportunities for animal players. For instance, if you're playing as a Cow, Deer, or Pig, seek out the Suspicious Cow, an NPC cow in the fields of Eltibule. She can sell you some animal-specific abilities, and even has a unique dye recipe that is otherwise unobtainable ("drab grass green"). She also sells belts for each of those animal forms. Werewolves should look for Sanja the wolf, in the forests off the coast of Kur. And every animal player will find it helpful to talk to Flia, a fairy in the wilds of Serbule.
NPC & Animal Interactions
Returning to Human Form (temporarily)
In order to make "being an animal" a viable path through the entire game, the next update (Sept 2014) adds some high-level Words of Power that can help. These Words apply an illusion to you that makes you look like a human for a minute or so -- just long enough to talk to NPCs that ignore animals!
Completing quests this way is a fairly laborious process, because you have to research the Words and each Word is usable only once. It is intended that being an animal is a hard play style. The "human form" Words of Power just ensure that animals can access important skills and equipment that they will need at higher level, even though it will be a bit of a pain.
To permanently undo the transformation to Cow, a player will have the kill the Maronesa boss in the Crystal Cavern.
To undo the transformation to a Deer, Rabbit or a Pig, a player will have to obtain a random drop Un-Deer potion or Un-Pig potion and drink that.
To undo the transformation to a Spider the player will have to obtain an Un Spider potion from the Strange Spider in Serbule Crypts (who is guarded by the tough Rhino Guardian).
Please note: once a player has transformed to a Lycan (wolf), that CANNOT be undone !
Trivia
Animal forms (and specifically Cow at first), was at first 'a fluke' by the Dev's.
Citan / Eric originally only intended the Animal forms to be a very temporary curse. Intended only as 'punishment' and to be cured ASAP.
He / they were surprised to find that certain players wanted to continue playing in that animal form. And subsequently the different animal forms and their abilities and playstyle were further developed.