Steve Backshall - who's quite famed for taking his top off, although sadly we can make no promises here - travels across the world to encounter the largest animals he can find and discover the remarkable things their size enables them to do. Highlights include Steve swimming with Nile crocodiles in Botswana, dodging two-tonne elephant seals in California and diving with sperm whales in the Caribbean. Before you get too excited, there could be wetsuits involved in all of the aforementioned, but that's unlikely.