Celestial Jeweller's Incubator has restrictions on where or how it can drop.
Drops from Legion encounters.
Recipes
Celestial Jeweller's Incubator can be created from the following recipes:
Amount
Part
Description
Meta
8
Parasitic PassengersParasitic Passengers810x Incubator Item Level:84Feeding on death, they grew stronger and stronger, until they were ready to hatch...
Random item level 84 incubator x10
A
1
The VoidThe Void1Reach into the Void and claim your prize.
Random divination card set exchange
A
The incubator will drop Elder or Shaper influenced jewellery, but not Thief's TrinketThief's TrinketCorrupted.