The Killer Clown Leader is the main clown in 'The Clowns Here Kill' Part 1 and 2. She is the one who killed JC. She is played by Alejandra Cejudo.
Episode 1 - The Clowns Here Kill Part 1
The Head Clown greets all the guests upon entering Everlock. It is presumed that she somehow stopped the Ferris Wheel from moving after Matt and Rosanna discovering their true intentions. She convinces Joey to play her game and gave him the Jack in the Box (unknowingly the first Artifact).
Episode 2 - The Clowns Here Kill Part 2
When JC and Teala got voted into the death challenge. Safiya had to save Teala and Matt had to save JC through a challenge, but Matt failed to do so, and the Leader killed JC by stabbing him repetetively.