Outside of the cities it is very different. There is a sharp contrast between the shining buildings of the metropolitan areas and what is now referred to as The Overgrowth. It is the mostly undeveloped area that allows nature to take over.
The creatures there are usually larger than most Terran animals. Generally speaking they are herbivorous but there is the occasional carnivore that is usually more brutal and durable than most other creatures.
Some people believe that there are native beings that have been living in The Undergrowth for a long time, but no evidence of them has ever been found.