Spawns animals on each continent according to three types of terrain groups - hot (desert/jungle), mild (plains/grass/forest), and cold (tundra/ice). The program will try to choose a number of different animals for each continent, but right now there aren't very many to choose from so you often end up with continents full of elephants and stuff like that.
More details in the thread.
Python Animal Spawning 2.1
Spawns animals in three types (pred/prey/plant) according to terrain.