Pyrolobus fumarii is the OG of heat-loving extremophiles. This tiny, badass archaeon, whose name literally means "firelobe of the chimney" calls boiling underwater chimneys home—specifically, the scalding black smoker vents at the Mid-Atlantic Ridge. It was among the first organisms to be discovered thriving in such extreme conditions, proving that life is way more adaptable (and stubborn) than we ever imagined.

What's really wild about this extremist archaea is that it actually "freezes up" and stops growing at a mere 90°C (194°F) - temperatures that would turn most living things into soup. For a hot minute, our fiery friend held the record for most heat-tolerant organism until Methanopyrus kandleri came along and stole its crown by surviving at 122°C.