Greatest thing is … those mugs are also available in Space Invader Design.

Normally the Pac Boy mug displays an empty maze and the Space Intruders mug displays a blank starry sky. But add some kind of hot beverage and instantly the Pac Boy maze is filled with 8-bit style ghosts and energizers while the Space Intruders shows a retro invaders style battle in action.

More info: Hot/Cold Arcade Coffee Mug (with awesome video)

- Related: Retro: Space Invaders Magnets / Retro Cool Space Invaders Alarm Clock / Space Invaders Door Matt