C4K0 was a protocol droid that operated during the waning years of the Galactic Republic.


During the time of the Clone Wars, C4K0 served as a guide for a Restimar Mining Corporation team in the crystal mines of the moon Tilnes, where the team was attempting to mine crystals as part of Operation Cracked Crystal, in violation of a trade agreement with the Verga Mer Mining Company. However, during the operation an electromagnetic pulse damaged C4K0 and the rest of the team's droids and equipment. The team attempted to dismantle C4K0 and use its parts to repair their equipment, but this caused the droid to become erratic and start attacking them.