"Superman II" villains, e.g

• "The War of the Worlds" foes, e.g
• Roswell visitors, for short?
• AP exam company
• Beings from out of this world, in brief
• Aliens, for short: Abbr
• "Independence Day" assailants
• "Star Wars" extras
• "Independence Day" foes: Abbr
• Big-headed sorts, for short

Wikipedia Word definitions in Wikipedia
ETS is an abbreviation of: