Black War Bear - For the Alliance/Horde Achievements.
The achievement is to slay the leaders of the Horde or Alliance. As I am alliance this will be mostly for the benefit of Alliance characters, but I will try to help the Horde too.
Requirements. You will want either a large, mainly level 80 guild, or a level 77+ Pug with several naxx/Malygos geared characters. Have at least 3 tanks and at the very least 5-6 healers. Also try to have several shadow priests for increased mana and health regeneration.
You will need to, as alliance, go after Thrall or Sylvanas first. As Horde, go for Wyrnn or Magni first. The reasoning behind this is that the Horde/Alliance will gang up against you on these bosses if you do not kill them quickly.
1. You will want to go in a back way if you can - for example, Undercity has the sewers, and Stormwind has the Harbor. First, Get in the Boss chamber and have your first 4 groups set up with AoE to kill the guards and any enemy players present.
Have groups 5-6 filled with your tanks and healers. Also throw in a Warlock or two with the imp for Blood Pact for increased health.
Groups 7 and 8 will need to be focus fire damage such as warriors and rogues, along with any other classes with group-wide buffs.
2. Once the guards are out of the way, focus fire the boss down while having group 1 continue AoE for the enemy players and guards that constantly show up. Presently the boss should die.
3. Never use the tram for Ironforge to SW or vice versa or the Zeppelin to Undercity to Orgrimmar or vice versa. The players will expect this and block you immediately!
Choose a completely random city to go to after your current one besides the one closest to you.
4. Rinse and repeat.
Tips: On Thrall have a separate tank and a rogue for Vol'Jin, as he polymorphs several people at a time and heals thrall.
On Sylvanas use a macro to target her every time she uses her blink ability, otherwise the fight will drag out too long and Horde will crush you.
Immediately after killing the last boss a mail will be sent containing the Bear from either Thrall or Wyrnn.
Happy Hunting!