Mine gapes at me at some point just about every time I handle him, he has never attempted to bite me. This is usually if he's about to walk off of the end of my hand and I need to grab him with my other hand, or when I hold him lower than my eye level. It's definitely the luck of the draw with friendly/aggressive chameleons. Between a scale of 1-10, with 10 being the most aggressive, I would place mine at a 4 or 5, while you probably have a 1.