An unidentified Lizard and K5

The brown lizard showed up at my back,, for the first time that I know...I am sure he has been around but I had never seen this big fat scaly thing...scary to think that he lives with us practically speaking..7yrs that I have lived here, I met him for the first time a few days ago. He did not ask for a portrait but I had to take a few photos since my son always says, "all the cool critters come out to see you when I am at school !". The green one is a commonly seen figure here, he turns from green to brown.. But the gigantic brown spotted scaly thing (the fattest part of his gut was nearly an inch and a half or two inch wide) stately stood with his head high.....