Hippo

Fantasy Fact: Dragons produced hydrogen in their guts, which produced fire when ignited by platinum.

Scientific Inspiration: The gut of all animals contains numerous bacteria. In humans, it has been estimated that each of our bodies contains more bacterial cells than animal ones. In many species, gut bacteria play a key role; for example, most plant-eating animals, such as hippos, are unable to digest one of the main constituents of plants, cellulose. Gut bacteria in a compartmentalized stomach do it for them.

One of the products of the activity of some bacteria is gas, such as methane and hydrogen. Both can be produced by bacterial fermentation in the human colon. It has even been estimated that this process could lead to the use of bacteria on an industrial scale, to generate hydrogen for use as a fuel.