Major Domo is a character from the 3-D film and theme park attraction Captain EO.
Major Domo is a robotic security officer on the ship captained by Captain EO. Another small robot, Minor Domo, fits like a module into Major Domo. He can transform into musical instruments and the other crew members begin to play the various instruments.
His name may be a pun on 'mayordomo' meaning Steward or Butler in Spanish.