Oil is a type of stain. It takes longer than most stains to clean up. It often indicates a Spydor attack. It can also be found in the Basement, under the Hot Rod in the Foyer, and above the fan in the Kitchen. When cleaned up, the player recieves two Happy Points.

By picking up the oil with the Squirter, Chibi-Robo can use the oil on a Utilibot to make them happy. There will be no happy points or Moolah gained from collecting the oil in this way though.