I tried to give him some chances (I myself have done a lot of dumb things (I will say for now that I got into some trouble on the Gang of Five Forum and got banned many times from the Jedi Council forums.) However, he isn't merely just not getting along with others, he's more like downright trolling. I tried to give him as much leeway as possible, even calling others off of him so that I wouldn't be a hypocrite for calling him out. However, he just won't stop.. (He even added, to his AKA "LilDevillePees". While he's been gone for three days, I'm not sure if he's gone for good.
He does need some kind of a ban. His behavior would have gotten him banned on other forums by now, but I think the time has come to at least give him a day ban or something so he gets the idea that it's time for him to behave with the fanfic and wiht the name-calling thing.
Also, beforehand, I had considered it possible, that, like myself, he might have some kind of disabiliity that impairs his ability to work well with others. However, his antics, plus the name he chose as his AKA, suggests more likely that he's actually underage. I cannot prove it, but his "MongooseLoverDies", and other things he's done are really chidlish more than they are of somebody who is trying to do well but just cannot manage it.
On the flip side, he doesn't appear to be deliberately trolling, as he hasn't harmed anything (other than to name call), besides fanfic pages and adding a few pictures to the cannon pags. (One of which was actually good and is being kept.)
I do think he has some maturity as he's trying to make a dinosaur gallery, which is interesting as it would show all the species in one group and could be a benefit to the wiki....if he put the right names. As it is, he has Cera and her father as a differnet species, Littlefoot and his grandparents as a different species, etc.