We've had our tegu for about 2 months now, and so far he's been very calm with us. He usually lets us hold him and we don't really have a problem handing him in general. However, yesterday, when we took him out of his tank, he started freaking out. He would simply not tolerate being handled and would start running away if he had the chance to. He would even try to wiggle out of our grasp, which he's never done before. He did get moved into a new tank recently. Usually we try to handle him once a day to once every other day for a half an hour or so depending on when he comes out of hiding. Not to sound like a worried parent but he's never displayed behavior before. 
