Related Clues:

• Neptunians and others
• Klingons, e.g.
• Federal agents
• S.A.T. org.
• 'Star Wars' walk-ons
• 'The X-Files' extras, briefly
• X-file examiners
• S.A.T. administrator
• Venusians, e.g.
• UFO passengers
• F.B.I. figures
• They can cover a lot of space
• Space invaders
• Visitors to Earth, for short
• Aliens, for short