Used to be I liked to say that cockroaches and pigeons and rats will inherit the Earth, but obviously water bears, aka moss piglets—or you can call them tardigrades if you want to get all sciencey (and I do)—will long outlast any of those resourceful but nasty jerks. Science-types also like to call tardigrades the "hardiest animal on Earth" because they've developed a highly evolved power-nap strategy that involves shutting down "all but the essential biological processes when conditions are not conducive to supporting life." Sounds like me at a Pottery Barn!
Tardigrades can live anywhere on the planet, from the Arctic to the Antarctic, from the Himalayas to the deep sea. In 2007, some Euronauts even chucked a few of them out into "harsh environment of open space" for 12 days and they lived. They enjoy a long lifespan and new generations form in a relatively short time (read: They fuck like bunnies and grow old like sea turtles.) Take that, great mountain burning with fire! Bonus animal fun fact of the day: Doves are just white pigeons, aka rats with wings.