The easiest frog to get at the Faire will be the Tree Frog. While you are enjoying the festivities, you might notice a small green orc child named Flik running around with his pet frog. If you can catch up to him, he'll sell you the frog for one gold, or less depending on your reputation with the Faire.
Congratulations! You now have a frog!
The second easiest frog to acquire is probably the Wood Frog. This is also sold by the small boy, but it is a semi-rare spawn. If you see one, snap it up quick! It is priced the same as the other frog, but is harder to get, especially if there are many players around. In fact, once you have one for yourself, it would be wise to stock up.
You are not the only one pursuing this achievement after all! Plan to sell your extra Wood Frogs before the patch, just after, or around the time of the expansion release on November 13th.
Preparation for the Jubling
The frog that is the most difficult pet to get will be your Jubling, although 'time-consuming' might be a better phrase to describe this acquisition.
Consider seeking a friend or guildmate with the [Direbrew's Remote] that drops from Coren Direbrew, a boss in Blackrock Depths that is only present during Brewfest. If you have your own remote, even better!
Bring at least 60 silver with you, and then hit the portal! I recommend making sure your hearthstone is not on a cooldown before you try this.
You'll arrive in an empty room adjacent to a room in the bar full of patrons. Enter this room, and run up the stairs to the second level, or platform. Run to the back of this area and look for a vendor with a red hat named Plugger Spazzring. He will sell you up to ten [Dark Iron Ale Mugs], and I recommend buying them all.
After you've browsed his wares, hearth home and head back to the Faire. You have everything you need to acquire your own Jubling egg that will hatch into your very own pet after one week.
Find Morja, a woman who may or may not have a blue question mark over her head. If you are having trouble locating her, click on Options (or hit the Escape key once), and select Interface.
Under the Game tab, select Names and make sure that NPC names has a check-mark next to it, then hit Okay. This will ensure that her name is displayed over her head.
If you find her and she does have a blue question mark over her head, you are in luck! Someone has recently lured her Jubling (JubJub) back to her and she is seeking some Dark Iron Ale in order to be able to lure him herself. In exchange for this, she is prepared to offer you one of JubJub's unhatched eggs. Simply give her the ale, and pat yourself on the back for a job well done!
If she has no quest above her head, you'll have to lure JubJub yourself. Good thing that you have your own stack of [Dark Iron Ale Mugs]! Simply plant one near her feet by clicking on it in your inventory and 'aiming' it where you want it to sit. Her pet loves this stuff, and should come hopping from wherever he's been exploring to lap it up.
Unfortunately, he does not always come on the first try, but he almost always shows up within three. Once he does, she will proclaim how much she missed him, and offer you the trade via the quest [Spawn of JubJub].
If you are a low level character who cannot make it through Blackrock Depths alone, and you have no friends with the remote, you might have to purchase the portal from someone else. Because it is on a one hour cooldown, you might have to pay. Another option is to scout the auction house for the drink.
On the other hand, if you can pop over there regularly, feel free to sell your extra brew on the auction house for others! Doing so might make you enough money to pay for the pets you purchased, and then some. Even if you can't make it back easily, you should have quite a bit of ale left over once you finish the quest.
In addition to listening to the songs of your new frog pets, you might want to stop by Blackrock Depths the odd time to pick up some more ale. Your Jubling just might have a hankering!