eLo
Congratulation for finding the Black Rat pack on your own but...
...this is actually a repost...from the elite section...
Originally Posted by
MoD
eLo!
I'd like to present you my very special/secret critter farming spot for Critter Kill Squad/Crittergeddon achievements:

As an intro, i''ll try to explain why I post this in the Elite section while I don't even have access to it.
I discovered those special critters deep in the Molten Core raid instance back in the early days of WoW Vanilla while wallwalking during a long wait between two Sulfuron pulls. I figured they were some sort of *not so intended* placeholder critters used for unknown mechanics placed there (usually out of reach/sight) among many others which could/can still be found in various instances/battlegrounds /around the world. I've since then only showed/talked about it to trustworthy/exploration-care individuals, and it seems that along all those years, the millions of players venturing threw failed to spot them, including you, I could bet! (they are not referenced on wowhead/thottbot/mmo-champion)
Now assuming this information is secret/unknown enough (can such a thing really be...), and seeing how Blizzard lastly seems successfull at hotfixing every unwanted ones, I'd be pleased if this specific one doesn't meet the same fate just a bunch of days after posting it here. By that I mean, use with caution & common sense, if you rush from 1k to 100k in less then an hour (which you can do if you stack 39 other guild members in the raid+instance!), it surely will draw Blizzard's attention.
As a final note: the spawn spot itself can be worth more/less & hard to reach/unreachable depending on your character class / skills at climbing up walls, but as every true exploration/experiment, it's really worth it!
Now starts the guide:

Once in the Molten Core, simply head to Sulfuron's cave. (Every boss/trash mob can be easily skipped if not killed at CLvL85, my iLvL345 Arms warrior can solo the whole instance including Ragnaros with ease)
The exact spawn spot is on top of a huge rock in the small lava-lake right before the boss, as shown on the picture below:

After jumping in the lava-lake, you can climb along the edge of the rock to reach a lava-safe spot, from which casters/pet-owners will be able to farm the critters. Melees will have to make their way up the rock by any mean, here are a few ways I can think of:
-Using character skills, aka legit ways: Charge, Heroic Leap, Intervern > pets, Shadowstep, Levitation wall climbing, Slow/safefall from Majordomo's platform, goblin racial, perfect wall jumping, angle climbing, trash mobs arounds, etc use your imagination!
-File editing, aka semi legit ways: Any convenient way you can think off, only limits are your imagination & implementation. I'm still enjoying my http://www.ownedcore.com/forums/worl...l-concept.html just fine!
-Haxorizering; aka the =0 legit ways: Bleh, hacks allow to reach anything with ease but suck for sure! (-1 Epenis)
Wether you manage to reach the top or not, here is the fact: The Super Molten Duper Black Critter Rat Blast Pack's there:

It consists of a untargetable/unkillable Black Rat critter staring at you, or rather, it's 7 killable clone brothers with a endless 0<->3sec. respawn timer, ready for massive slaughter!

This spot will reward from 3.5k. in an hour (solo) to 100k in less then 30 minutes with a complete 40 guild members raid in the instance.
~
Here is a video of my warrior farming while afk with a Attack/Thunderclap maccro spam using _keyspam by DrakeFish, dual wielding Ravager, and getting the achievement.
I made these article/pictures & released this guide for Mmowned Elite section only, don't post the whole/part of information/images of this article without my strict approval as I take full credit for the whole discovery/method/exploit detailled here.
Comments @ dis/likes welcome, thanks!
It's still the best spot in the game to get the achievement, now that you've exposed it let's hope it will stay...