Related Clues:
- Not from Earth
- Not terrestrial, perhaps
- Sci-fi film extra
- An American in Paris, e.g.
- Not terrestrial
- Not natural
- Xenophobe's fear
- With 27-Down, sci-fi phenomena that help explain this puzzle's theme
- Border crosser
- 1979 sci-fi thriller
- Nonnative
- From another planet
- One with a big head?
- Out of this world?
- UFO occupant