Primordial Bogling
Drops from Bog Beast. The sludge that can give rise to the dredgers has been known to coalesce and run a muck. Magic type. You need to have the world quest up to be able to get this pet. When that quest is up, there is a chance to spawn the , which can drop the , which teaches you this pet.
The Primordial Bogling is a battle pet obtained from the 
Bucket of Primordial Sludge, which has a chance to drop from the Bog Beast in Revendreth during the world quest Muck It Up.
Guide awaiting review
Activate Muck It Up Quest
The Bog Beast can only spawn when the world quest Muck It Up is active in Revendreth. Check your world map for this quest before heading out, as the entire encounter is tied to it being available.
Collect Primordial Muck
While on the Muck It Up quest, enemies drop 
Primordial Muck. Collect as many as possible, up to a maximum of 20, without throwing any yet — any unused Primordial Muck is removed from your bags when the quest completes, so hold onto them until you are ready.
Join a Raid Group
Before throwing any Primordial Muck into the pool, join a raid group through the group finder. Throwing Primordial Muck into the pool while in a raid group gives you more chances at spawning the Bog Beast, since each piece thrown is a separate attempt and you can pool your collected muck across the group.
Throw Muck, Spawn Beast
Head to the Bog Beast spawn area at 37.26, 30.1 or at 32.8, 32 in Revendreth and throw your Primordial Muck into the pool. Each throw has a chance to spawn the Bog Beast — you have a limited number of attempts equal to however much muck you collected, so throw while in the raid group for maximum attempts.
Defeat and Loot Bog Beast
When the Bog Beast spawns at 32.8, 32 in Revendreth, defeat it and loot it for a chance at the Bucket of Primordial Sludge, which teaches you the Primordial Bogling pet.
Tips
When Primordial Bogling is out as your active companion, it will occasionally slime your character, applying the Covered in Muck effect — a yellow-orange color change that lasts 20 seconds, accompanied by a squelching sound.
The color of the Covered in Muck effect can shift to a different hue depending on the color of the mount you are currently riding.
See the video guide for a visual walkthrough of the Muck It Up quest and Bog Beast encounter: https://youtu.be/NwhTUPHyODk
