Aspan

The Aspans are a species from the mobile game Valerian: City of Alpha. They are a part of the radioactive class in the game, and are one of the 3,236 species of the space station Alpha. According to the book of the film, they come from Eos, a planet with a toxic atmosphere that only they can breathe or else they die. That is why their masks are filled with chemical components of their homeworld's atmosphere.