Cluster (Steven Universe)

The Cluster is the name of a massive gem monster and is mentioned in ''Steven Universe. ''It is a giant Cluster Gem that is currently incubating deep beneath the Earth's core and is said to be larger than the Earth itself and it will destroy the planet once it reaches its final form. The Crystal Gems are currently working to stop The Cluster from reaching its final form.

Season 1
The Cluster is first mention in the season one episode Jail Break where Peridot arrives on Earth with her escort Jasper and her informant Lapis Lazuli. Peridot looks at her objectives and she is sent in to investigate and check up on The Cluster.

Season 2
The Cluster is mentioned again in Catch and Release and is explored in greater detail. After Peridot is able to form some sort've truce with the Crystak Gems, she is freed by Steven and she takes him to the Kindergarten where she brings up the monitor and she shows Steven a map fo the Earth and the location of where The Cluster is at. Peridot then reveals to Steven that once The Cluster is finished incubating, it will grow to become larger than the Earth itself and it'll destroy the entire planet. Peridot then reveals that once The Homeworld saw Earth as no longer a viable colony to mass-incubate gem warriors, the homeworld had began experiments involving the forced fusion of Gemshards to create some kind of "Gem Geo-Weapon". She then reveals in the Prime Kindergarten Control Room that the Gemfusions they Crystal Gems had fought before, were actually prototypes for The Cluster and reveals it to be a massive giant comprised of millions of gemshards and once it reaches its final form, it will grow to become bigger than the Earth and the whole planet will be destroyed if it's not stopped.

Ever since Back to the Barn, the Crystal Gems and Peridot have been working together in an effort to stop The CLuster before it can reach its final form and destroy the Earth. The gems are currently trying to build a drill so they can make it to the Earth's core and stop The Cluster from incubating but no progress has been made so far.