Rescuing an Adult Male today - Need serious advice!

Hi All!!
While I know quite a bit about BP's and rescuing them, I have never rescued one in quite the situation this guy is in.
Let me tell you a bit about him and what is known of his situation.
What's known - He's a male. Age? Unsure. But due to his size, he's an adult. He has not been handled in atleast 4 months, his husbandry was not up to par, he will not eat f/t and due to lack of handling/care/ and good husbandry practices, He is aggressive.
What I know to do - I have already set up a quarantine area just for him and only him. I have a new enclosure for him (40Gallon - He was in a 20 Gallon with no heat source :( ) with Aspen Bedding, Heat and humidity already going and fresh water, 2 hides and privacy. I have already made an appointment with the local vet for him to get checked out to make sure he is not sick. It wouldn't suprise me if he is ... If he is...I will go from there with that news.
I'm concerned about his aggressive behavior and since he is an adult how to break this. I know how to do so with hatchlings and yearlings but am unsure when it comes to an adult who has been neglected for so long. The gentleman who took him from his negligent owner says he refuses to eat F/T, only live and absolutely will not eat if there is any light or anyone in the room. *loud scream of frustration* This poor guy!!!
Any and all advice would be appreciated. I want to do right by him. He deserves it. His aggression WILL NOT keep me from showing him love and care. Again, he deserves this new life.

What constitutes "aggression"?

When a hand or tongs come inside the viv he will attempt to bite (I dodged his bite upon meeting him yesterday...but fear I wont be so lucky next time).
If you walk past the viv he is in at the foster home he will hiss and snap at it. He wants no part of interaction.
He seems to "puff up" if you so much as look at him.
He seems more fearful and defensive rather than "Aggressive".
You can tell he is very uncomfortable with people and my guess is it has been MUCH longer than 4 months since he has been handled.
The negligent owner didn't even have a hide provided for him so he has been ignored and exposed with no means for feeling secure and hidden.

Poor guy, some BP's are a bit more grumpy than others, but I would suggest something besides a viv to make him feel a bit more secure. A nice dark tub, just right for his size, with hides to make him nice and secure would probably go a long way toward cutting down on that type of behavior.

If all you have available is a viv clutter it up something fierce and provide lots of places for him to hide.

If that doesn't work just prepare to get tagged. It's not that bad. Either he will figure out the behavior doesn't make him be left alone or he will just continue it. I have a king that is a bitey lil sucker no matter what you do. He's a jerk but he's our lovable lil jerk. Best of luck!

Also old paper towel roll to sort of "boop" him out of bite mode can be helpful.

Thank you :) I do have a big dark tub and lots of stuff for him. I did know that might be an option so I prepared for it (I was shopping foreverrrr yesterday after I met him. He's already so spoiled and aint even home yet! lol) I am prepared for his bite and have read alot about continuing to handle and not be afraid of him and to show him that no matter if he bites I still care and wont ignore him. I wish I had more of a back story on him, but rescuing means that is not readily available. I am hoping his visit to the vet answers a lot more of my questions on age and health. This guy just deserves to be happy, even if I get bit in the process of making him happy :) If snakey is happy mommy is happy :D:snake::oops:

I hope he does well for you!

As do I :) Thank you for your advice :)

Since you already have the tank and set up you might consider taping some dark paper to all sides. Leave a gap up front so you can check on him without disturbing him. As things progress make the opening larger.

Definitely don't touch the tank at all if possible for at least a solid week so he can settle and feel secure. Almost ignore him. Don't worry about feeding until the next week or longer depending upon his last feed.

It probably wouldn't hurt to get a 3 ft snake hook just to get him out of the tank. They are not expensive and easily obtained on the net. Once he is out he will probably chill. If gloves will boost your confidence for at least the first time there is no shame there.

Good on you for taking him in! :)

I have already bought a snake hook on my shopping spree yesterday :) I almost feel I went overboard on buying things for him. I would rather be overly prepared than under prepared for this new adventure. I do like your idea of dark paper on all sides and fully planned on no interaction for atleast a week. He ate a large rat the day before yesterday, I am hoping he will eat in a couple of weeks (2 or 3) once he is fully secure in his new home. My hope is once he see's he is safe and in a good place in life his defensive behavior will settle. I do have gloves (Welding gloves - they're almost better than snake gloves! lol) but am going to try not to use them so he see's I have no fear of him and that I am not the enemy. :)

Get his husbandry correct and let him settle in and he may settle right down on his own. No heat source and poor conditions he's probably miserable and no wonder he not too pleasant. Get him comfortable and settled in, a couple of meals in him and he may be just fine.