Slayer's Felbroken Shrieker

This is a Demon Hunter Class Mount.

Warning: In no-fly areas when you jump with the mount it looks like its gliding, its not, you will take full damage upon reaching the ground!

Edited for clarity.

The below is accurate for anyone who is completing this on an alt. You do not need to do any zones/reputations/quests to get this to work. This presumes that:

• 
  
• You have completed Legion questlines/required content on a main previously.
• 
  
• You have taken & skipped the questline to get to Dalaran from Orgrimmar/Stormwind.
• 
  
• You got into your Class Hall.
• 
  

Since I did not find updated information for completing this on an alt easily, here is what I found, accurate as of the moment the changes were made to open all appearances to alts if a main completed the requirements in Legion (so 2023 and onwards, for sure):

1. 
   
2. Complete Uniting The Isles @ Khadgar in Dalaran - again, it is not required to have any reputation or do any pre-requisites. Go to Violet Citadel, take and turn in the quest instantly. You will need this to get WQs to do for your Class Hall campaign. You can do this at any point once you enter Dalaran.
3. 
   
4. Finish A Glorious Campaign achievement (your Class Hall campaign) - it takes roughly a couple of days, depending on your effort, but does have some timed missions you will have to do. Note that you can focus on the CLASS Campaign rather than the ARTIFACT Campaign - check your quest log to see where the quests fall if you are unsure. You will need to do the initial weapon quest and maybe a couple to set up your hall, but you don't have to get any reputation or go to any Legion zones to quest. I'd recommend doing all the artifacts for every spec just to have them and not get confused. Completing this should award you the Class Title at the end. If you did not receive it - you have not finished! Make sure you also complete the Heroic Weapons quest that pops up after the last quest of the campaign.
5. 
   
6. Start Legionfall Campaign @ Krasus' Landing in Dalaran. You can skip ahead and not do the scenario.
7. 
   
8. Grab the Champions of Legionfall quest from Maiev - if it is not available, you need to finish your CLASS campaign. You don't need to do any other quests in the zone.
9. 
   
10. Head to your Class Order Hall.
11. 
    
12. Take and complete the questline for the new champion offered to you.
13. 
    
14. Once completed, you might see a quest on the map in your hall, but you can't take it/find it - go to Legionfall in Broken Shore again, submit Maiev's quest, and you should be able to start your mount quest right there. The mount quest is picked up in Legionfall, but it can take a second to load in. If you are not seeing it, try relogging.
15. 
    
16. Do the quest to obtain your mount. This will unlock all mount options that exist.
17. 
    

Congrats, you are done! Some rewards may require extra effort, but all are available to get after these steps.

Some of demon hunter's unique Class Hall rewards are:
Slayer Title
Felbroken Shrieker (Mount)
Hateful Eye (Pet) - can also be received in the warlock Class Hall
Skull of Corruption (Toy)
Tiny Set of Warglaives (Toy)

You can refer to other rewards/classes in this great guide:
Class-Specific Toys, Mounts and More!