You should go for a monitor like a Nile, Water or Black Throat. They are really great and as for a reptile, they are very smart and if you get them as babies and interact with them a lot, they get puppy dog tame. My old Nile monitor was so tame, I used to come home from work and throw him in the tub with the heat lamp on and he would relax in there and then walk around the apartment. For some reason though, he hated a friend of mine and took a swipe at him with his tail so hard it put a divet in the wall and broke the sheet rock. If that had connected with his leg, he would not have been feeling good.I wish I could get another monitor but no way I got the room needed indoors to make a cage the size a full grown large one needs.