In MUX canon, the Coil began as an inner circle of Cobra loyal to Serpentor during the Cobra Civil War. When Serpentor was killed, most Cobra returned to the fold, but some where not satisfied with Cobra Commander's return to power, and continued meeting and plotting in secret. Following Cobra's collapse in the early 90s Firefly began working with Mikihali in recruiting former Cobra assets to The Coil.