Well, you have to kill them all so start from the top and go down. This may take awhile, so be patient!

Blade's Edge Mountains

1. Hemathion Ogri'la (all around )
2. Morcrush can be found east of Death's Door, southwest between 73,30 and 61,53, he can also be found west of Gruul's Lair around 60,24
3. Speaker Mar'grom Patrols around the entrance of Gruul's Lair, as well as Bloodmaul Outpost, and Bladespire Hold

Hellfire Peninsula

1. Fulgorge Can be found around 51,70 34,56 and 26,50
2. Mekthorg the Wild Found around Zeth'gor and also around Hellfire Citadel
3. Vorakem Doomspeaker Patrols around The Legion Front, The Pools of Aggonar, and also south of the Throne of Kil'jaeden 60,31

Nagrand

1. Goretooth Found around Halaa, Sunspring Post, East of Kil'sorrow Fortress, and also in the lake by the Throne of the Elements
2. Voidhunter Yar Patrols around the circle at Oshu'gun

Netherstorm

1. Chief Engineer Lorthander He can be found around Manaforge Ara, Manaforge Duro, and Manaforge Coruu )
2. Ever-Core the Punisher Found around Manaforge B'naar, Manaforge Ultris, and Manaforge Ara
3. Nuramoc Can be found near Forge Base Oblivion, patrols between Arklon Ruins and Manaforge B'naar, and patrols the road north of Manaforge Duro from 67,62 and 54,60

Shadowmoon Valley

1. Ambassador Jerrikar Can be found at Dragonmaw Fortress, Eclipse Point,Northwest of Wildhammer Stronghold, South of Coilskar Point, or East of The Hand of Guil'dan
2. Collidus the Warp-Watcher Between Black Temple and The Altar of Sha'tar, Between Dragonmaw Fortress and Sanctum of the Stars, or around The Deathforge
3. Kraator Found at Eclipse Point, Warden's Cage, The Deathforge and North of Coilskar Point

Terokkar Forest

1. Crippler He patrols the Bone Wastes circle or inside Auchindoun
2. Doomsayer Jurim Patrols the road from Shattrah to The Bone Wastes, also from Shattrah and Tuurem, also between Tuurem and the Bonechewer Ruins
3. Okrek He patrols between the tree top huts in any of the Arrakoa Veils in the forest

Zangarmarsh

1. Bog Lurker Found around the following coordinates 23,25 47,60 and Between Cenarian Refuge and the entrance of Zangarmarsh from Terokkar Forest
2. Coilfang Emissary She patrols between Umbrafen Lake and The Lagoon, and Marshlight Lake and Serpent Lake
3. Marticar Patrols the roads between Ango'rosh Grounds and the Spawning Glen, patrols the north side of Serpent Lake, and east of Telredor