One of the Animals I did expect to see in the tropics, is the Australian Water Buffelow. Also known as the Swamp Buffelow, these are an introduced spiecies here in the Northern Territory.
These Animals were introduced from Timor and Indonesia in 1824 and 1849. Most of the buffelow here are exported to Vietnam and back to the Indonesian Islands as livestock for meat. Apparently they tase quite good and are worth a lot of money. However, many buffelo can still be found wild here in the NT.
Although useually black in colour, I managed to find a white one here below. Deceptivly, there are in fact a very large animal, and you do want to keep your distance from them.