Post Haste

To obtain the pet you dont have to do this on the advanced mode, you can do it on the basic (as long as you complete the 30 letters).

If you have someone with you give them the following list. Read them the names that comes up during the challenge and your friend answer with the corresponding number. That number is the position of the stack to click. Easy as that!

Allerian Stronghold = 3
Altar of Sha'tar = 3
Area 52 = 3
Arie Peak = 2
Astranaar = 1
Azurewing Repose = 6
Booty Bay = 2
Bradensbrook = 6
Brill = 2
Camp Oneqwah = 4
Cenarion Refuge = 3
Conquest Hold = 4
Cosmowrench = 3
Dawn's Blossom = 5
Deliverance Point = 6
Everlook = 1
Feathermoon Stronghold = 1
Frosthold = 4
Gadgetzan = 1
Garadar = 3
Goldshire = 2
Greywatch = 6
Halfhill = 5
Honor Hold = 3
Kamagua = 4
Kharanos = 2
Klaxxi'vess = 5
Lion's Landing = 5
Longying Outpost = 5
Lor'danel = 1
Lorlathil = 6
Menethil Harbor = 2
Meredil = 6
Moa'ki Harbor = 4
Nesingwary Base Camp = 4
Nighthaven = 1
Nordrassil = 1
One Keg = 5
Ramkahen = 1
Sentinel Hills = 2
Shackle's Den = 6
Skyhorn = 6
Soggy's Gamble = 5
Stonard = 2
Sylvanaar = 3
Tarren Mill = 2
The Argent Stand = 4
The Crossroads = 1
Thrallmar = 3
Thunder Cleft = 5
Thunder Totem = 6
Tian Monastery = 5
Tranquillien = 2
Valdisdall = 6
Valiance Keep = 4
Warsong Hold = 4
Whisperwind Grove = 1
Wyrmrest Temple = 4
Zabra'jin = 3
Zouchin Village = 5

1 = Kalimdor
2 = Eastern Kingdoms
3 = Outland
4 = Northrend
5 = Pandaria
6 = Broken Isles

Most I can get is 21... old reflexes I guess.