Oil

Oil is an obstacle in the game Donkey Kong on the Game Boy. It first appears in Stage 1-1 in the Big-City, later appearing in Stage 1-2 and much later in Stage 8-11 in Rocky-Valley. It consists of fire in a tin resembling an oil drum with the text "oil" written on it. It floats up and down in place without trying to attack Mario, but touching it is deadly. It can be defeated with the hammer.

Oil reappears in Mario vs. Donkey Kong and behaves the same way, with the can now even more resembling an oil drum.