Kosumoth the Hungering

Kosumoth the Hungering (Eye of Azshara 46, 52) is a rare who doesn't drop anything valuable but is required for the world quest DANGER: Kosumoth the Hungering.

You're probably looking for the mount [item=138201] or the pet [item=140261].

The reward of DANGER: Kosumoth the Hungering is one of those.

To obtain the World Quest you have to meet certain critea:

• Speak to [npc=102695], he's located at the Broken Shore around 37, 71
• 
  
• Find [item=139783] which is located at the Broken Shore at the cave around 57, 52
  in order to enter the cave you probably have to die first and enter the cave as a ghost.
  At the end of the cave you will find a tiny little pile which you have to loot.
• 
  
• Go back to [npc=102695] (Broken Shore 37, 71) and speak with him again.
  (Note: You'll have to speak with him several times)

Activate the Orbs in this order:

1. Orb:
   Fly to Azurewing Repose (Azsuna) and go to 37.96, 37.41
   Cave Entrance Orb#1
2. 
   
3. Orb:
   Fly to Lorna's Watch for Alliance (Stormheim) / Crimson Thicket for Horde (Suramar) and go to Stormheim 32.92, 75.90
   Cave Entrance Orb#2
4. 
   Note: try to avoid the elite ;)
   
5. Orb:
   Fly to Lorlathil (Val'sharah) and go to 41.51, 81.18
   Cave Entrance Orb#3
6. 
   
7. Orb:
   Fly to Dalaran and glide down to the Broken Shore (Broken Shore) at 29.16, 78.57 and dive until you will see the underwater cave entrance
   Cave Entrance Orb#4
8. 
   
9. Orb:
   Fly to Felblaze Ingress (Azsuna) and go to 59,37, 13.13
   Cave Entrance Orb#5 Orb is litte bit hidden: Location of Orb#5
10. 
    
11. Orb:
    Fly to Shield's Rest (Stormheim) and swim north until you see this:
    Orb#6
12. 
    
13. Orb:
    Fly to Skyhorn (Highmountain) and go to 55.84, 38.47 (you need to jump down a bit)
    Cave Entrance Orb#7
14. 
    
15. Orb:
    Fly to Azurewing Repost (Azsuna) and go to 54.02, 26.18
    Cave Entrance Orb#8 Orb is a bit hidden: Location of Orb#8
16. 
    
17. Orb:
    Fly to Eye of Azhara (Eye of Azshara) and go to 79.52, 89.31 and swim down to the sunken ship
    Cave Entrance Orb#9
18. 
    
19. Orb:
    Go back to [npc=102695] (Broken Shore 37, 71) next to him is the last orb
    Cave Entrance Orb#10

Last Step

• Go to Kosumoth (Eye of Azshara 46, 52) and now you should see the World Quest Kosumoth
• 
  
• Slay him

FAQ:
Orbs?
These Orbs looks like this.

You can't use them?
Make sure to do it in the correct order!

You forget which was your last orb?
Try out this macro, its awesome! /run local t={["1"]=43730,["2"]=43731,["3"]=43732, ["4"]=43733, ["5"]=43734, ["6"]=43735, ["7"]=43736, ["8"]=43737, ["9"]=43760, ["10"]=43761} for k,v in pairs(t) do print(k,"is",IsQuestFlaggedCompleted(v) and "done" or "not done") end

I'm lazy! HELP!

/way Broken Shore 37 71
/way Broken Shore 57 52
/way Broken Shore 37 71
/way Azsuna 37.96 37.41
/way Stormheim 63.06 35.53
/way Stormheim 32.92 75.90
/way Val'sharah 41.51 81.18
/way Broken Shore 29.16 78.57
/way Azsuna 59.37 13.13

/way Stormheim 67.26 14.90
/way Highmountain 55.84 38.47
/way Azsuna 54.02 26.18
/way Eye of Azshara 79.52 89.31
/way Broken Shore 37 71

Do you have to redo the "questline"?
No! You don't have to do this pain again! The World Quest is weekly and the rewards change every two weeks.

Credits go to
Blackfaded
Arcten

Thx for the awesome macro wilddron!

Did i miss someone? Tell me! :)

This summons Kosumoth the Hungering!

Go to [npc=102695] at 37, 71 on Broken Shore Map and talk to him. Then go to cave at 57,52 on the broken shore and click the mud at the end of the cave to get the [item=139783] you need. Then go to [npc=102695] at 37, 71 on Broken Shore Map again and give him the relict and talk to him several times until he wants to leave him alone. After that click all the orbs in the right order!

Clickable order:
1. 38, 37 Cave Aszuna
2. 32,75 Stormheim
3. 41, 80 Val'sharah
4. 32, 72 on Broken Shore Map
5. 59, 13 Cave Aszuna
6. 67, 14 on World Map, under the neutral shark is the cave entrance
7. 56, 38 Highmountain
8. 53, 26 Cave Aszuna
9. 49, 90 on World Map in the sunken ship
10. 37, 71 on Broken Shore Map

This will summon the Boss and give you a Worldquest to obtain the [item=138201] mount or the [item=140261] pet! I think it changes weekly.
After clicking the last orb a region wide message appears:

Azeroth itself recoils as <name> unleashes an ancient evil.
Kosumoth the Hungering walks the land once more...

Thanks to all people who helped figuring this out.

EDIT: User Demoic posted a nice script to see if you have clicked an orb already:

/run local a={43730,43731,43732,43733,43734,43735,43736,43737,43760,43761}for i,q in ipairs(a)do print(format("Orb %s: %s",i, IsQuestFlaggedCompleted(q) and "\124cFF00FF00Done\124r" or "\124cFFFF0000Not Done\124r")) end

Thanks to him!

EDIT 7th Sep: Read post above by Blackfaded. The boss is summoned using a particular method of activating orbs in the correct order, and the mount and pet rewards seem to be based on a weekly quest.

Information:

Kosumoth the Hungering is located in the center of the physical Eye of Azshara island in the south of the Broken Isles (NOT the dungeon version).

Kosumoth has 83.42M health baseline and requires a group to defeat. His health increases/scales up with more than 5 people. He has 3 main abilities; Shadow Bolt Volley, Gluttonous Shadows and Void Fissures as well as melee attacking:

1. 
   
2. Shadow Bolt Volley is the most deadly. It is a 2 second cast that that deals around 10M damage to all enemies (eg: wipe damage) so NEEDS to be interrupted. It seems to be cast every 8 seconds so a rotation of two interrupters should be fine.
3. 
   
4. Gluttonous Shadows is a 15 yard radius AoE around Kosumoth that deals a large amount of shadow damage to anyone stood in the area and may also heal him(?). This damage isn't deadly, however the cast can be interrupted so if you have spare interrupters they should interrupt this. The spell has a 2.5 second cast and seems to be cast randomly every 15-25 seconds.
5. 
   
6. Void Fissures is a 1.5 second cast that summons 8 small adds. These adds have low health and don't really seem do much except melee-attack, so should simply be quickly AoE'd down. This ability seems to be cast every 15 seconds or so.
7. 
   
8. Apart from his main 3 abilities he also melees at a slow and unsteady pace. This damage however isn't significant and any healer should have no issue keeping the tank alive.
9. 
   

Here is my YouTube video, which has two kills where you can see Kosumoth and his abilities in action: https://www.youtube.com/watch?v=isDeBtus-Kk