Board Thread:My Singing Monsters Forum/@comment-25404524-20191009061010/@comment-31797469-20191010131739

Plixie is the only celestial that only requires Plant Island to fill.

Honestly though, by the time you should be worrying about Celestials, you should have already filled Wublin Island with Zynths, got a Bonus Breeder on all Natural Islands and some Mirror Islands. With that egg breeding throughput, all Celestials will be a breeze.