Invertebrate Oil 

Invertebrate Oil
Binds when picked up
Use: Teaches you how to summon this companion.
Binds when picked up
Use: Teaches you how to summon this companion.
Uncommon
Yes

Ground
Bubbles and idles about.
Unknown
None
3 allowed
Shadowlands
Patch 9.0.2 | Posted: October 13, 2020
To spawn the rare that has a chance of dropping this pet, players must interact with the Pool of Mixed Monstrosities located South of Plague Watch Flight Master in Maldraxxus.
Defeated slime mobs nearby will drop an object that can be interacted with and carried to the pool. Adding 10 of each colored item, Viscous Oil (red), Miscible Ooze (yellow), and Mephitic Goo (blue), will summon the rare creature that can be looted once per day per character.
Defeated slime mobs nearby will drop an object that can be interacted with and carried to the pool. Adding 10 of each colored item, Viscous Oil (red), Miscible Ooze (yellow), and Mephitic Goo (blue), will summon the rare creature that can be looted once per day per character.
Level 0:
0
0
0



1-1 of 1
1-1 of 1

Cross Gazer and Willy are currently the only other pets with both Rot and a Critter attack to capitalize on the type conversion.
However, this one is an extreme pain to get. Not only is it a low drop chance off of a named that takes a lot of time investment to spawn, but the event that triggers it can be influenced by any player in the open world resulting in one of the other six named being triggered instead. Then you have to start over from scratch and try again and pray.