6G-66, nicknamed "Sixer," was an astromech droid in service to the Resistance during its war with the First Order. 6G-66 flew in the T-70 X-wing starfighter of Jessika Pava during Black Squadron's mission to gather allies and bring new systems into the Resistance. Though Pava noted Sixer was less than thrilled about it, due to Pava being known as the "Great Destroyer" by the astromechs at the Resistance base on D'Qar, she added there was no way she would fly the mission without an onboard astromech as it was too important.