We had an iguana and I was surprised at how smart she was. She had us well trained. She would scratch on the terrarium door (4'x4' sliding window) when she wanted out. She was potty trained on newspaper under a computer desk - easy to clean. When she wanted a bath she'd clamber upstairs and trundle off to the bathroom and climb in for us to fill it. When done she'd hop out onto a waiting towel.
Unfortunately, she was too smart for her own good. We have a cat door and by watching the cats she figured out going through it meant freedom outside. First time she did it a neighbor called to say our giant lizard was on her bedroom window screen. So we blocked the cat door with a heavy box when ever she was out. She'd sun at the window there and look outside. One day she had the idea she could wedge herself between the wall and box and push it away from the cat door. Bad move as it was well below freezing that Nov night. We didn't find her till March, desiccated up high in a tree still attached to the limb.
Great pet, though.