Conversion of the stored chemical energy of the brown adipose tissue (BAT) into heat by rodents, difficulties in energy storage by cheetahs, conversion of the nutrient's energy into electric power by electric eels and requirement of unreasonable amounts of energy storage by Albatrosses to exhale flame are evaluated. Humans are born with BAT activity but lose it in a short while. Scientists are trying to bring it back as a therapeutic procedure against obesity. Electric eels need to hunt a large number of low‐calorie catfish in a single electric shock. This is possible in prosperous places like the Amazon, but not elsewhere. Wandering albatross might have been perceived as a dragon, if it would have the flame exhaling ability. It may yield the production of 116 mol of methane after being fossilized. If the entire energy stored by the fossil should be used for exhaling fire, it would be sufficient for 17 days only. Its lifespan is more than 50 years, even if the albatross uses all of its stored energy for flame exhaling its energy will fall too short to achieve it for the lifetime. Energy conversion processes, which are described in this study are achieved by limited number of biological species only and appear in the literature for the first time.