I was an avid player of Pokemon Crystal and absolutely loved the game. It was hard not to when I had a Thick Club-armed Marowak with both Rock Slide and Bonemerang that hit everything like the fist of an angry god. Since Blizzard announced the new pet battle system for WoW, I have also been a fan of that -- never mind that it wasn't actually in the game until recently. If tear-assing around the world with a small, vicious creature that smites your enemies is wrong, I don't want to be right.
The pet battle system went live on a recent beta build for Mists of Pandaria, but I was one of the players afflicted with the crash bug on entrance to the actual battles. Suffice it to say that it is difficult to evaluate something when you are driven offline by doing it. However, that was fixed, and even though a bunch of LUA errors are still driving me out of the game at times, I return with tidings of great joy for prospective owners of dynamite rabbits.
You'll also find our early collection of pet battle posts helpful, although some of the information collected there has been overtaken by recent events.
Warning for those browsing on mobile devices: This is an image-intensive article.
Some of the stuff I learned didn't seem immediately obvious or intuitive, so here's an FAQ. Please bear in mind that aspects of pet battling are quite buggy right now, and I apologize if I've missed anything during my own play time:
What will they train me in? Both trainers will give you two abilities, one active and one passive: Battle Pet Training, which allows you to train and fight with your pets in addition to tracking wild ones on your minimap, and Revive Battle Pets, which will resurrect all of them to full health anywhere you are at the cost of a 15-minute cooldown.
How much does the training cost? At present, it's 80 gold for a player at exalted with Stormwind/Orgrimmar.
Is there any type of pet that's best? Every pet type has advantages and disadvantages, as with Pokemon. You will probably be battling beast and critter-type companions for the most part while you're starting out. If you want an early advantage, pick a speedy pet that takes less damage from one of these types and/or has an attack that does additional damage to them.
For purely sentimental reasons, I started battling with my Black Tabby, a beast-type that has a slight speed advantage over other level one pets and possesses Claw, which does extra damage versus critters.
As with classic Pokemon, it's likely that certain pet types or even specific pets will turn out to be unusually useful.
Will wild pets initiate fights? No.
I was somewhat surprised to discover that unlike Pokemon, you "kill" the enemy pet/s in a match.
Is it easy to find battles out in the field? This seems to vary by zone. So far, it's been rare for me to go more than a few yards in Durotar without encountering another option for a battle. In The Barrens, your options are a lot more sparse.
How quickly do I level up? As with Pokemon or your WoW characters, you'll level very quickly at first, with more and more experience being required for subsequent levels. As an example, my level 5 Black Tabby now requires 280 experience to level, getting about 80 XP per fight versus level 1 and level 2 critters out in the wild.
Can I switch pets so everyone gets experience? This is another Pokemon feature that's survived. Yes, you can switch pets to ensure that experience is shared, which is useful if you have a weaker or damaged pet that you still want to get XP.
I won, but my pet got injured. How do I heal it? Some pets have healing abilities, but you won't be able to use them outside of battles. The local stable master in every town and city will be able to heal and revive all of your pets.
Can I be attacked by wild mobs or other players while battling? I don't think you can be attacked by mobs (at least, it hasn't happened to me yet), but you can be attacked by other players.
I'll have a more comprehensive look at pet battling achievements soon. What I can say is that the huge array of new achievements spread between the collecting, fighting, and leveling sub-classes will keep both dedicated achievement hunters and dedicated pet battlers busy for a while.
Most interestingly, you can unlock pet battle daily quests by doing achievements.
Can you evaluate the difficulty of a battle before it starts? Look at the enemy pet's level; it's a rough guide to how much damage or speed it'll have. Pet levels vary by zone in the same fashion that mobs do. However, how difficult a match will be between pets is also affected by any damage or defense boosts they'll gain versus your pet's type.
Is there anything somewhat disturbing about pet battles? I have to admit that the idea of fighting to the death with your Curious Wolvar Pup or Curious Oracle Hatchling is equal parts hilarious and horrifying.