What it looks like you have there is somebody's iguana that either a)escaped or b)was abandoned (i.e. "freed"
. Either way, it does not look like he/she had a very good owner. I say this because it looks like this iguana's jaw/lips are malformed. This probably happened due to poor diet/husbandry, or from ramming his face against the glass of a tank in an effort to escape.
He is also a bit skinny, and despite having been in what looks like a sunny area, does not have a very good coloring. I am thinking it is a male, because I see orange coloring on his legs. This happens when they are in mating season, more to males than females. If he is in mating season, watch yourself and your family members. Iguanas can get violent and angry during this time.
Can you get a picture of his under belly, especially the thigh area? Then I can tell you more accurately if you have a boy or a girl there.
So what's it going to take to keep him alive tonight?
First of all, if you have the tank on the floor, get it OFF the floor, right now, high off the floor. Maybe on top of a shelf, or at least on top of a table or dresser. I bet you he will stop freaking, or at least calm down a little. Covering his tank with a sheet will also help, he is probably very scared. He may also be attacking his reflection. You can tape paper on the inside walls of the tank, and he will not be able to see his reflection any more.
Next, the food needs to be chopped up smaller. Do you have a food processor? Chop up his food to about the size or rice. He will be more likely to eat it. If you don't have a food processor or chopper, you can use a cheese grater. I used to use the old lids of peanutbutter jars or tupperware for plates. It works pretty well, and it's disposable.
You can try to tempt him into eating by offering him dark leafy greens like collards, kale, mustard greens, dandelion, escarole, rocket, frisee, or endive. The easiest way to get this stuff is to buy a bag of pre-cut salad greens (Dole makes a nice blend) from the grocery store produce aisle. The one I use is called "Spring Mix", I think.
Good fruits to try are: mango, papaya, kiwi, banana, apple, blueberry, strawberry, raspberry. Avoid citrus fruits, they can burn.
It would be good to put a bowl of water in there with him, and to spray his food before he eats is. Don't worry about him hating you, it's only a negative thing if you've trained him to think that. Given his current condition, I doubt if anyone's ever paid enough attention to him to train him to do anything.
If you're feeling brave, you might want to try to give him a luke-warm bath. He may be constipated (and therefore uncomfortable and grumpy) from eating unfamiliar foods in his adventure in the wilds of Virginia. An inch or two of luke-warm water is usually a natural inducement to iguanas to go potty.
The tank will be fine for the next couple of days. I'd leave him alone as much as possible, although I know that won't be easy! If you have some time in the next couple days, and a screen porch that you're sure he won't get out of, you might let him roam while you're there, to get used to you and to get some sunlight. Remember, glass and plastic windows will block out almost all of the rays iguanas need from the sun.
I'm in Maryland, so I know that it's pretty hot down in Virginia today. If you don't have air conditioning in your house, he should be all right with a human heating pad (covered with a thin fabric cover) on low or medium, underneath his belly. Do you have any kind of thermometer? At night his temps should be around 80. Don't let the heating pad get hot, and don't let him lie on it uncovered. It can cause burns.
If it's colder than 80 degrees in your house, what you can do is use a heating pad, plus get a LOT of chemical hand warmers (skiers and hunters use them a lot) and put them in individual socks. At bedtime, surround the iguana with these "hot socks", and insulate the cage well with a few blankets. Don't cut off all the oxygen, though!
Keep him away from any other pets you have.
Wash your hands after EVERY TIME that you touch him.
You can try petfinder.com to see if anybody lost an iguana... but trust me, people very rarely report that. Sad, but true... I have "found" two iguanas in the past 2 years, without looking for them in any way. (The first one is my own pet now, and the second one I placed in an adoptive home.)
Good luck... we are here if you need anything. How old are you? Think hard about keeping this iguana. He will probably live for at least 10- 15 more years. I am 23 years old, and have had my iguana for 2 years.
I can honestly say that I am rounding down when I tell you I have spent more than $3,000 dollars nursing my rescues back to health, and housing them, and feeding and taking them to the vet, and paying for a petsitter which is almost impossible to find for an iguana. And all the other ways you have to adjust your life to care for a huge animal that other people are scared of, that isn't usually appreciative of what you are doing for it.
Iguanas are great, but think really hard about this and involve your family/significant other. Even if you are my age, you will need their cooperation and sometimes their help, even if you think you never will. Someday you will be sick, or away at school, or late from work, stuck in a blizzard or your car will break down. Think of what's best for everybody. Everything is easier if the people you live with/near think it is okay to have an iguana. Everything is harder if they don't!
Here is an adoption link if you want to explore the option of putting him up for adoption. There are lots of great people out there looking to adopt. 
If you haven't already, check out http://www.anapsid.org. Get Melissa Kaplan's book "Iguanas for Dummies", and or James Hatfield's book "The Ultimate Green Iguana Owner's Manual". If your local library does not have it handy, ask them to do an "Inter-Library Loan" request.
You did a great thing to rescue this ig.
-Erin
Green Iguana Society Adoption Board
