No idea. There’s several theories of what our dreams mean and I don’t think anyone has really come up with a conclusive answer. Are our brains clearing out the day’s stimuli and trying to put it into categories? Are we dreaming out our anxieties and fears that we try to avoid or deny when awake? Are we working out problems? Is our brain just pulling out various things from storage to act as white noise while it rests? The only thing that can be deduced from dreaming about your chameleon, is that you think about and care for him a lot.