One of the scariest sights to see are the crocodiles laying in wait ready to chomp into their victims and drag them under the water. Whenever you see a body of water you just need to start looking close and you will eventually see them. They are good at blending in and/or looking like logs floating in the water.
The above pictures were taken with a Nikon D90 at 300mm. The picture with the croc in the water was taken much later in the day at ISO 1600.
The first picture with the croc on the reddish soil was taken in Kruger Park at the map location below