From http://rationalwiki.org/wiki/Life: "A wildfire demonstrates the characteristics needed for life based on some definitions and is often cited as an example of where the definitions present ambiguity or non-intuitive consequences. Fire "breathes" oxygen, consumes food (wood or other fuel), grows (expands across the solid fuel), reproduces by division or by spreading spores (embers) through the air, and eventually dies while excreting waste ash. Sensitivity and reaction to surroundings is more difficult, but fire does react to water by retreating or dying. By the definitions involving energy, fires can consume energy in a controlled manner, however, their primarily destructive nature makes them fail at being alive using definitions based on information or evolution.
Interestingly, even though fires may spring to life spontaneously under the right conditions, and there is no obvious physical link between various individual fires, they all appear to be very closely related - or even identical - in terms of their chemistry."
Also check out MRS GREN: the seven characteristics of living things.