Well, to be perfectly honest, it is completely normal for iguanas to be aggressive. They truely do not make very good pets unless you start from a teeny tiny lizard and work him up. All I can suggest about that is patiently working with him for a little while every day and hope it comes around. Don't stress him out too much though, just enough to get him used to you being around and slowly work up to seeing if he'll let you touch him, and then work on trying to pick him up. Step by step, it may take several weeks... be patient.
The black spot on his head could be any number of things... I would look at his heat source, make sure his basking lamp is far enough away so he isn't getting burnt by it... but I doubt it is that if it comes and goes. Its probably nothing. Make sure the UV light is working and not too old... the fluorescent ones are only good for about 6 months.
As for feeding. What are you trying to feed him? When igs get stressed, they frequently go off of feed... but best place is to start with some really tempting food.
The Iguana Den has a pretty extensive list of stuff you can feed your ig... go through the list and try a few different things and see if anything tempts him. Try to avoid lettuces though. Once you find something he likes, it is most likely going to be something that isn't exactly the best food for him - iguanas are great at knowing what they shouldn't eat too much of - try mixing in some
collard greens and other good stuff with it.
Rav
