I used to have a female veiled chameleon. Any time we got near the tank it would puff up and clearly get all pissed off.
I traded w/ the store for a male panther chameleon and let me tell you, any time I open the doors on his tank to feed him he doesn't even look at the crickets and somehow finds a way to cling onto my shirt. He always wants to come out no matter if its someone he's never seen before or not (btw, he is about 1.5 years old)
My female panther chameleon (breeding the 2 together in the future) is starting to get more used to me and comes out a bit more often but lately has not been eating or drinking much so I will have to get that one figured out.