Can we have creatures that fly over the mountains and main roads? For example birds that you could kill for meat or poultry, or turn in for eggs over the main roads, and over the mountains something a bit more aggressive? And if you are flying and crash into one of these things, you can lose balance or fall out of the sky?

And if you fly over the forests, spiders could shoot out webs at you (thinking of the glomdoring ones here) and bring you down to their nests?