Tiny Flamefly

To get this pet, you must complete a series of quests in Burning Steepes.

In The Burning Steepes, begin at Flamestar Post (coords: 17,53) and accept the two quests from Ariok (Burning Vengeance) and from Mouton Flamestar (Done Nothing Wrong).

After you turn those two quests in, Ariok will have Stocking Up, A Future Project, and Mud Hunter available.

Once you turn those in, he'll send you to every warlock's favorite vendor, Gorzeeki Wildeyes for The Sand, the Cider, and the Orb.

Gorzeeki will then give you two quests: Warlocks have the Neatest Stuff and Shadow Boxing.
He'll send you back to Ariok then you'll be sent to Chiselgrip. [Chiselgrip coords: (45,44)]

In Chiselgrip, Eitrigg begins a new quest chain with A Needle in a Hellhole. Thus begins A Perfect Costume quest chain.
(For Undead Female, total materials are 2 hide, 4 mud, 2 thread)
(For Draenei Female total materials are 4 hide, 1 mud, 3 thread)

EDIT: Note: to get the General Throg'izog step, you HAVE to do the quests offered by Stebben Oreknuckle in Chiselgrip: Prove Yer Allegiance, Scrapped Golems then Golem Training.

After you've completed the Trial by Magma step and received the bludgeon, Eitrigg tells you to go abuse your power. I Am the Law is not required to be sent to Flame Crest.

Finally, at Flame Crest, Kibler will offer Not Fireflies, Flameflies.

EDIT (Alliance version).
In place of Ariok and Eitrigg for Allaince is John J. Keeshan and Colonel Troteman.
As well as Morgan's Vigil and SEVEN! YUP!

BluExocet's description is correct.... Also... the correct Hide/Mud/Thread for a NE Male is 3/2/1 ... And the Alliance equivalent of the quest that rewards the flamefly is called "Seven! YUP!".... Basically do all the quests you can do @ Flamestar Post in Burning Steppes.... then it will send you to Chiselgrip.... Do all those... then the quests will send you to Thorium Point where you will receive the "Seven! YUP!" quest. It took me all of 20 mins as an 80 to complete all the required quests... everyt

This pet is a purple/green reskin of the current pet Firefly. It has similar animations to the firefly and cleans its face (while idle) aswell as flies.

How to get it
Alliance: This pet can be obtained by completing the quest SEVEN! YUP!. The quest is the end of a chain and the first quest can be obtained at Thorium Point, Searing Gorge. The first quest in the series is called Abuse of Power.

Horde: This pet is rewarded from the quest Not Fireflies, Flameflies. The quest is the end of a chain and the first quest can be obtained at Thorium Point, Searing Gorge. The first quest in the series is called Abuse of Power.

- All information taken from Warcraft Vanity.