Originally there were going to be two huge alien spaceships looming over Earth: an Arquillian ship and a Baltian ship, with representatives of both species staking claim of the galaxy. Mr. Rosenberg (the "little dude in the big dude's head") was a Baltian (confirmed by the novelization of the film), while the tall alien (
Carel Struycken) he met at the restaurant was an Arquillian (and is so listed in the end credits). After some choice editing and rewriting, Rosenberg became an Arquillian.
more