Since then I've been on a mission to get all the pets I wanted from the game, and today, with the capture of my ideal Core Hound*, I've completed it.
http://www.the-yarn.net/images/wow/Pet_Wall.png
The image is too big to put up directly, but the pets in order are as follows:
Tier 1: Active Stables
Loquenahak - (Northrend Spirit Beast - Rare Spawn)
Skoll - (Northrend Spirit Beast - Rare Spawn)
Terrorpene - (Mount Hyjal - Rare Spawn)
*Chromaggus - (BWL Boss)
Deth'tilac - (Molten Front - Rare Challenge Spawn)
Tier 2: Inactive Stables
Skarr - (Molten Front - Rare Challenge Spawn)
King Krush - (Sholazar Basin - Rare Spawn)
Sambas - (Twilight Highlands - Rare Spawn)
Undead Eagle - (Icecrown - Common Spawn)
Purple Shale Spider - (Deepholm - Common Spawn)
Tier 3: Keepers
Anthriss - (Molten Front - Rare Challenge Spawn)
Madexx Blue - (Uldum - Rare Spawn)
Madexx Bronze - (Uldum - Rare Spawn)
Black Devilsaur - (Un'goro Crater - Common Spawn)
Tier 4: Whim Tames
Jadefang - (Deepholm - Rare Spawn)
Kirix - (Molten Front - Rare Challenge Spawn)
I have a few more pets in the stables, but none really I intend to keep too long come Mists.
Did all these solo, and the most challenging were definitely Deth'tilac and Chromaggus.
Deth'tilac because the tame itself is long, tricky, and open to griefing galore by Horde & Alliance players alike. Best to tame him in the space he spawns in. It involves a lot of traps, pet sacrifices and kiting like mad. It took about 5 goes, because he kept evade-resetting just as I got him to 19% and tamable twice, twice he killed me with Deth Strike (doh), and on the tame, an Ally hunter turned up waiting her go - no pressure!
Chromaggus wasn't a tricky tame per se, in fact it was a straight forward tame beast cast, but getting to him, solo, however was a real challenge. The challenge in fact was getting past Razorgore, and working out a way to despawn the two waves of adds that come in, without having Razorgore blow the room up by de-aggroing. Then killing the remaining adds (including the controller at the very last) all without losing aggro on Razor himself before getting to hit the mind control orb to start destroying eggs. Spent a good 90 minutes or so in that first room repeatedly wiping over and over until I got the technique and timing down. Best thing about all that? You can't do it with an active pet. So you have to do it pet-free.
Skoll was a hard one too, but that was just a matter of routing the spawn points in Storm Peaks for nearly 5 hours solid today. Ditto for Terrorpene, which was another camping trip.
To say I'm proud of getting ALL the pets I wanted inside of 3 days of hitting 85 would be an understatement. Now I can start getting geared up for raids
/relax

