South Africa's largest lizard is the Nile Monitor Lizard, growing to a total length of just over 2m. It's smaller cousin - The Rock Monitor Lizard - in this photo - grows to just over 1,5m.
These lizards have a forked tongue like a snake, large thick tails and vice-grip like jaws.
They use their tails to defend themselves by whipping an intruder.
If one does bite you and does not let go, there is nothing you can do to open the jaws. From personal experience I have learnt to just sit it out and wait for the Monitor Lizard to let go on his own. It can take up to 30 minutes or so. If you try and open the mouth, it just grips harder. I've tried putting it under water - it just holds its breath and bites harder!
The Rock Monitor can tame down and make a wonderful pet. I've yet to see a Nile Monitor tame down.
This photo was taken in the Kruger National Park