Start as a plant or animal making first landfall half a billion years ago, then evolve it on drifting continents in the face of competition and huge ecological events: Win if become the dominant herbivore or carnivore.

In the full game you can grow from 200 grams to 20 tonnes. The atmosphere is tracked for oxygen, cloud cover, and greenhouse gases, and the decisions the players make influence the climate.

Bios Megafauna comes with 8 "continents" that can drift around, 160 mutation cards, 140 wooden laser-cut creeples of flying, burrowing, swimming, and armored creatures, various tokens of fossils and monsters, 110 wooden cubes, 42 climate disks, and 20 dice (mainly to track creature size). For the full game, there are 3 latitude strips and a climate board that tracks oxygen, clouds, and greenhouse gases. The game is the second game of the "Bios" trilogy, which can be played together or separately.