Fransesite

Artist's depiction of what a Fransesite might look like.

The Galactic Fransesite Empire is the mortal enemy of Earth, and is constantly at war with the Royal Space Navy. Although no human has ever seen a Fransesite, it is rumored that they are vile, scaly creatures with horns and tentacles. It is known that they breathe Argon and secret sulfuric acid from their pores.