The Clay Monsters are villains that appear in "Little Gift Shop of Horrors". They were originally pieces of clay but they were brought to life by black magic used by Harry Claymore. They however betrayed their creator when 3D computer animation was invented making them no longer needed in claymation movies anymore.
List of clay monsters
It is the leader of the clay monsters and the one seen that can talk. It captures Soos and Stan Pines and put them in clay to turn them into clay. When Mabel conquers her fear, she fights the Cyclops by turning it into the Star clay monster because it is made out of clay. It then turns good and helps Mabel defeat the other clay monsters.
They attack Dipper and Mabel to capture and put them in clay to turn them into clay. But Mabel escaped and turned the Cyclops monster into a Star monster to fight them, killing them all. They are the only clay monsters to hold weapons, such as swords and shields.
It was the Cyclops clay monster that was turned into a Star clay monster when Mabel knows that turning something she is scared of into something that she likes can help conquer her fear, so she turns the Cyclops into a Star because the Star is a character from a movie she likes. It then helps Mabel defeat the other clay monsters.
Medusa with a scorpion body (shadow)
It appears and fights the Star clay monster but instead got mixed with it into a big block of clay.
Four unicorns fall from the above to join the battle with the other clay monsters but instead dropped on them and mixed into a big block of clay thus ending the battle.