The Mammal Kingdom is a branch of evolution in the main simulation. It becomes available once the player has unlocked Tetrapods, but to unlock the first Generator on this branch, the player must spend Metabits. Because of this, the Mammal Kingdom can only be accessed once the player has rebooted the simulation for the first time by reaching the Singularity.
Generators and upgrades in this tree are purchased with Entropy points. Different families of mammal are unlocked using Metabits.
Types of Mammals
There are six families of mammals included in this branch: The Marsupials and the Monotremes are each a separate section, and the Eutherians are sub-divided into the Glires, Feliforms, Caniforms, Ungulates and Cetaceans
The Marsupials feature Koalas, Kangaroos, and Opossums. The Monotremes feature Echidnas and Platypi. The Glires feature Rabbits, Beavers, Squirrels, and Rats. The Feliforms feature Snow Leopards, Lions, and Tigers. The Caniforms feature Grizzly Bears, Polar Bears, Foxes, Pandas, Seals, Walrus, Wolves, and Honey Badgers. The Ungulates feature Camels, Gazelles, Ibex, Deer, Buffalo, Hippopotamus, Rhinoceroses, Zebras, and Elephants. The Cetaceans feature Dolphins and Whales