neutered netherland still aggressive

I've had my bun, Lucifer, for about 8 months. He is about 10 months old. Up until 4 months ago he was a very cuddly sweet little guy. Then he hit puberty and became a little aggressive. He would charge at me or the cats (we have 2) but nothing more. Two months ago I had him neutered and when he first came home he was even more aggressive. He started growling/snarling, charging at people and the cats, and biting. Hes bitten me 6 or 7 times hard enough to break the skin and draw blood. Usually he does this when hes under the couch and someone is sitting on it (he just sees feet). I was under the impression he would have calmed down by now. He is a little less aggressive but he will bite out of nowhere for no apparent reason. He will be cuddled up to me and I am petting him when all of a sudden he snaps his head toward my hand and bites. If anyone can give me any advice it would be appreciated. I love my little bun and am willing to do whatever it takes, he means everything to me.

keep a towel between you and him. Block off access to under the couch.

There are different types of aggression, hormonal and learned behavior. It sounds like this is something your rabbit has learned to do, either out of fear or to get what he wants. So you are going to have to basically retrain him to not do this.

I agree that if the behavior is particularly associated with certain places he is at(eg. under the couch), then blocking off that area is a good first step. It can also be linked to particular actions you are doing, such as nipping you because you stop petting him and he doesn't want you to stop cause he thinks he's the boss in this relationship and he's telling you to keep petting. So you will need to address what you are doing that is reinforcing this behavior, so that when it happens you are not rewarding him(eg. you stop petting, he nips, so you keep petting him, which may be what he wanted).

Some things you can try are giving a loud 'eek' when he bites to let him know he's hurting you. Using gloves so that when he bites you don't take your hand away and inadvertently reward the behavior by doing so. Mimicking a dominant rabbit by gently(you don't want to cause injury) but firmly holding down his head for several seconds. Redirecting him to something positive before a nip occurs, by offering a treat or something positive. Clicker/treat training will sometimes work too.

This link had some helpful suggestions.
http://wabbitwiki.com/wiki/Aggressive_rabbits

Understanding how rabbits communicate with each other is helpful to know as well.
http://language.rabbitspeak.com/

Other suggestion... rename him! He may just be living up to his name

OK, i used a sheet to block of the futon. A couple times he charged but when his face caught the sheet he stopped immediately and I saw took lift his head and try to look around. It was funny, he didn't know how to react That is no longer a problem.

He hoped into the couch and trust to bite, I gently pushed his had down to make him submissive. He was absolutely OUTRAGED! The second I let go he tried to bite, I did it again. When I released him he looked offended and so angry. He gave me the Bunny death stare, then settled in next to me, he was eyeballing me though. He sat there, when he thought i wasn't looking and tried to bite. etc long story short, he's starting to act like his usual sweet self. It's been over a week since his last attack. Yesterday he issued a tiny griowl and half-heatedly acted like he was going to bite, but i could tell he wasn't even trying
thanks for helping us, I'm a newbie so it's awesome to have such knowledgeable folks take time to pass along their wisdom!!

Well, you chose a nethie... Netherland dwarfs are notorious for their foul temper, for being hyper and for biting. Of course, each rabbit has their own character, but all the netherland breeders I've talked to discouraged people from taking nethies for children because of the biting thing. I remember one who told me that she let children hold her lops and big bunnies but never any polish or nethies because it was scratch or bite everytime.
I have a nethie and a dwarf lop, had another lop previously. The nethie is definitely the least friendly. The first time I took her to vet she scratched him so bad he was bleeding all over and told me 'Your rabbit is MONSTER!" which was hilarious.

It also sounds like your rabbit is very dominant and has a particularly foul temper. Well, you DID call him Lucifer XD.
He will probably mellow with age, but it takes years. Aki, my nethie, has been a lot mellower past her... fourth year. Giving her a husbunny to boss around also helped - she used to make him give her back rubs and to steal all his carrots (no, seriously). She is now 7 and you can syringe feed her meds without losing a finger. So, there's hope for you yet!

But yeah, no more couch for the little devil. He's got to understand who is boss (Aki never turned on me but my little sister slept in my room when we went to my parents and Aki gave her HELL, even pissing on her bed and stuffs). At least, since he's neutered he's not spraying urine on it. That's a comforting thought, right? ^^