This is a Spotted Tree Monitor who normally lives in the roof of our big old open-sided shed. We named him Claude (clawed) after the first time we heard him trying to climb up the outside of the iron roof (think fingernails screeching on a blackboard!).
His tail is almost as long as his body so he's about 35cm from tip to tail. I was lucky to get this shot on the palm tree at the front of the house - when he sees you he usually shoots round the other side of the tree to be out of sight.