Shadowy Oozeling
Drops from Memory Cache. The perfect pet if you love stepping on something wet in the middle of the night. Magic type. If you are having issues like me finding this pet, there is a super easy way I over looked.
The Shadowy Oozeling is a wild pet found exclusively in the Maddening Deep zone during The War Within expansion, requiring a special environmental buff to even see it.
Guide awaiting review
Travel to Maddening Deep
Head to the Maddening Deep and stand in one of the puddles found in the zone. You need to gain stacks of Unseeming Shift by clicking a puddle — at least 5 stacks are needed for the Shadowy Oozeling to become visible, though 50 stacks will also cause a Voidling to spawn.
Search Known Spawn Locations
Once you have your Unseeming Shift stacks, check these confirmed spawn areas: at 66.4, 77.6, at 61.2, 77.8, at 63.8, 87.2, and at 58.7, 59.8 in the Maddening Deep. A fifth location has also been confirmed at 74.46, 60.36 in Azj-Kahet.
Target a Backline Pet
The Shadowy Oozeling is easier to find as a backline pet rather than a frontline fighter — one player found theirs as a backline pet to a Chitin Burrower at 74.29, 76.66 in Azj-Kahet. If you only find critter versions, kill them to help trigger a battle pet version to spawn.
Tips
The Shadowy Oozeling can combo Prowl with Call Darkness — Call Darkness deals humanoid damage, making it strong against Dragons despite being a Magic-type.
A power breed is useful for one-shotting enemies, but not strictly required since Magic-types are generally underpowered, making this combo valuable for family-specific achievements.