When Tatooine freezes over

"You can have your shockball cards back...when Tatooine freezes over!"

- A seriously annoyed parent

 is a euphemism for never or infinity commonly used throughout the galaxy, since nearly everyone thought of Tatooine as "the planet water abandoned". The phrase is so popular, that Darthipedians have used it on numerous occasions, including by the evil admins when they ban a troublesome user for good.