Bloodbrood Whelpling
Source: Vendor. Unlike other wyrms, blood wyrms drain their foes rather than consuming them whole. Undead type. Getting this pet requires completing the achievement on a Death Knight, then finishing the follow-up mount quest that starts at Deliverance Point with .
The Bloodbrood Whelpling is a pet vendor item sold by Slimy that requires Death Knights to complete specific artifact weapon progression and questline achievements.
Guide awaiting review
Complete mount questline
Complete the Breaching the Tomb achievement on your Death Knight, then finish the follow-up mount quest that starts at Deliverance Point with Amal'thazad's Message. Once you earn the Deathlord's Vilebrood Vanquisher mount, the pet becomes available for purchase.
Unlock Concordance on artifact
Achieve Power Ascended on your Blood-spec artifact weapon 
Maw of the Damned by maxing out all empowered artifact weapon traits plus one additional level.
Purchase from Slimy
Visit Slimy near the portal of Amal'thazad's Chamber in Acherus and purchase the Bloodbrood Whelpling for 
1000 Order Resources.
Tips
If you are obtaining this pet in Shadowlands or later, you only need to complete the mount questline once. The three whelpling variants all become purchasable from Slimy without requiring additional weapon questline completions.
