The central conceit of Terra Mystica is that mystical creatures are reliant on geography, in the sense that witches hang out in forests, halflings love a well-fertilized plain for planting pipe-weed, nomads roam the desert, chaos magicians build their crazy towers in the wasteland (where else?), and dwarves mine the mountains. And because each race is only interested in their own geographical feature, they’re bent on terraforming the entire world until it’s just one unending forest or rolling plain or scorched desert.
Which sounds awful, now that I think about it. Not that it’s going to keep me from transforming as much of the world as possible into lakes so my mermaids can frolic until the end of time.