In the world of Fairyland, there are many pets. These would normally roam the countryside, and you would fight them, however, pets can be caught by Beast masters, and tamed also. The higher it's level, the harder it is to capture and tame. If the pet is of too high a level for the owner, it will be uncontrollable.
Each type of pet has several elements, which defines its colour, they also have advantages against other types of elements:

Earth, Water, Fire, Wood, Metal, Light, Darks (View resistance's here:)

You will receive your first pet on your first quest for the village head, this will be in the form of an egg, (Which shows up in your inventory and must be right clicked to provide yourself with your "pet") which is one of two different ways they may be obtained. You can also capture pets towards the end of a battle, providing you are a Beast master(Very Rarely can a non Beast master Catch a pet),

Although pets are mostly eager to assist their owner, each pet, when assigned a function, draws a small amount on the owner's magic points. If that need cannot be met, the pet will return to normal function (You will lose Intimacy when this happens). If this happens too frequently, and the pet is of very low intimacy with its master, the pet may decide to flee from its master altogether, even though this occurrence is very rare.

One of the biggest advantages to having a pet is that it can also learn skills to assist you. Each type of pet can learn different types of skills, and some are even able to learn extra skills according to their element as well as the "learning slots" that are Available to your Pet. Not all skills are available to a pet, and they can only learn a limited number of those skills available (Learning Slots), so choose carefully, for example, a mage may choose to have a Light Gem Crawler as a combat pet because it has the ability to cast recovery, which is an elemental skill, to heal allies, and combo, which allows the pet to attack an enemy twice in one turn.

Pets also have a primary attribute. This determines their growth pattern (Refer the learning slot's on the Detailed pet info page). Again, using the Gem Crawler example, the primary attribute is Strength, which make it a reliable choice for combat. But beware, choosing a pet is not so easy. Because each pet has an elemental attribute to it, there is also a rival pet with an attribute which is strong against it. For example, if you are a swordsman, and you have a Flame Tiger as a combat pet, this might be effective against metal and wood enemies, running around trying to attack Water Monkeys in Rosen Lake is probably not the best idea, just like adding the pet to your armour wouldn't be such a good idea, as water is strong against fire, and they would be able to hit you easier, and for more damage. Each map in Fairyland has two contrasting elementals so that combat takes on a challenge.

Each "race" of pet has a number of skills it can learn, for example a Bear can only learn 2 skills from it's available list, and also a primary attribute, which defines the stat will will grow the most each level. Additionally, each element of the pet will have a different growth pattern, for example dark pets grows in Intelligence, so back to the mage example, a mage needs a pet to assign to magic to enhance the spell effect, whether this be healing, damage, or something else. Therefore, a dark sheep makes a perfect choice, as the sheep also has a primary attribute of Intelligence. When assigning a pure intelligence pet to magic, it will cause the effect of that magic to increase dramatically. Furthermore, a black sheep is level 1, so it does not require resetting!
(Also Refer to Detailed pet info page for information of the Race/Learning slots/Skill slots that are available to that Species)

Different assignments affect stats in different ways, for example a Pie Aibo for defense. Being a wood creature and an Aibo, it has a pure constitution growth. Your enhanced attack and defense skills can be found in your inventory. With the above 3 pets, I would probably be looking at training in placed like Moonglow, Secret Plains, or Candy Mountain. But I would have to be careful of metal enemies. Secret Plains has more earth than metal for example, so I may be safer there! On the subject of defense, assigning a pet to soul will allow greater resistance to magical attack.
(Separate Note: If you are choosing a combat pet or Armor pet you must make decisions based upon a few different values I'll give a few examples below)
A wood aibo grows as follows Species:Con Element:Wood (con growth) This means that It will grow primarily in "Hit Points" this means it can take a beaten and keep ticking. However! it's attacking power is greatly diminished this means that a Wood Aibo if put on as a Defense pet will greatly enhance your defense. (Aibo's species also has the ability to self heal as well as transfer HP's to their masters, greatly used by all classes)

There are other "important factors" that effect how well you are hit by a monster as well as how much damage you deal. You have just read about the defense ability of a pet. now I'll tell you briefly about AC.

AC: is your Armor Class The Higher your armor class is, the more damage you can take and "absorb" or not take damage at all!(That is why having higher AC for Trader's or Martial Artists make a big difference, and why Earth Bombs are sought after.)

Another pet is a Earth Aibo. Earth Aibo's grow as follows: Species - Con, Element: Earth - Grows in Con and Luck. This means that yes it grows the same way as a Wood Aibo, however where the Wood Aibo would have a Higher defense (because of the CON, CON growth)but lower AC the Earth Aibo will have higher AC and a lower defense.

Level 44 Earth Aibo (con:119 luck:103, HP'S:1650 Defense:1190) Putting on Armor slot I receive a : Defense boost of 368, AC boost of - 90

Level 50 Pie Aibo (con:184 luck: 24, HP'S: 2411 Defense:1840) Putting on Armor slot I receive a Defense boost of :540 , AC boost of - 14

A quick run down of the Attributes relevant to your characters

Dexterity - Effects Your chance to flee a battle, chance to deal damage before Pet's/Monsters can deal damage to yourself,

Strength - Effects how much damage you deal when you hit a Pet/Monster as well as how much you can carry at any one time.

Luck - Effects chances of finding rare items randomly (More luck means higher chances of rare finds). As well Luck effects almost every other skill in some manor or other. When fleeing Luck plays a part as well as dexterity. When dealing damage luck helps you by the possibility that you will deal more damage / a critical hit. and Luck also effects your Hit rate. Your hit rate determines your odds / chances of avoiding a hit directed at you. (on a level 40 black sheep, using goodwill hit rate increases by 430 points)

Constitution - Effects how much hp's you receive upon leveling, the more con you have the higher your chance of receiving large quantities of HP's when you level.

Charm - Charm is primarily used by beast masters. it effects your ability to capture a pet into a capsule. as well when you open a capsule it effects the base "intimacy" of your pets.

Intelligence - Effects a few major features. if you are a Mage it effects how much damage you deal when using a spell (This is why a black sheep is so desired in the magic slot) this increases your magic spell's effectiveness by about 20% or more). Also the higher your Intelligence is the more Mana you receive when you level (a Primary concern for mages). (Note: There is a rumor that Intelligence will make a major decision in how well all the other attributes effect features and spells in future patches.)

Work Production: This is the backbone of the game's Finances. Starting with Basic workskills Harvesting, Farming, Fishing, Hunting, Woodcutting and Mining. All of which are very important in furthering the Production Skills / Advanced Skills. Ranging from Apothecary, Armor Making, Metal working and much more all Found here: (Work Skill List Basic and Advanced )

Work Production with a pet's Stat's. By using a Black sheep with Goodwill you increase your successes of making better, and more powerful items. One example is Jewelry Making, Basic no goodwill usage you will receive a basic yield in production work. Say you make a STR ring, however this ring will only be say a +1 Stat. However using the Goodwill spell on a pet with high Intelligence you will receive a better chance of making +2, +3, +4, or even rare rare chances of +5. which Selling in the Goldburg Market will give you a higher amount of money then NPC (Non Player Character) selling to the market. (Example: 1 ring sells for say 200coins normally(to the shop NPC) however if it has good stats (Say) Str+3 you can sell in market setting up a Stall and pricing the ring for 1,500 coins. You are now on your way to making money.

The In game Cash System is : "coins" and you can purchase items from a number of sources. Work related tools are purchased at the Shop's and guilds. Armor shops, Breweries etc also sell work related items and tools. You may purchase items from the Goldburg Market on Server 1, This is the location that is dedicated to Resale of your hard worked materials. You will see things from low level basic work skills all the way to advanced high end equipment. Prices can vary as demand is needed for different Items. (1 coin all the way up to millions) Please keep in mind that only certain things are truly worth the really expensive prices. By working hard and making a lot of necessary items you help the community with equipment in demand or even services. Thus increasing your wealth and your options for purchasing other "items" that you value.

I hope you enjoy your Game Play Experience. Have fun.
MeFisher.