Ah, the useless things I wonder in the hour after waking.
Today, it’s how many Simpsons characters have been given middle names. Over umpteen seasons, they’ve been able to create a very detailed world, and sometimes it amazes me how detailed.
I assume a decent number of characters have had middle names mentioned at some point, either in plot points or one-liners, but with the exception of the Simpson men and one or two more significant secondary characters, I can’t think of them.
So far I have:
Homer Jay Simpson
Bartholomew Jojo Simpson
Charles Montgomery Burns (kind of cheating, I know)
Selma Bouvier Terwilliger Hutz McClure (Stu) Simpson
Milhouse Mussolini Van Houten
Otherwise, nothing. I could have sworn Lisa was “Lisa Marie Simpson” and would assume Marge would go the take-your-maiden-name route and be “Marge (or Margaret) Bouvier Simpson.” Some of the other big supporting cast members, like Flanders, Moe, the Wiggums, Skinner (or, for that matter, Tamzarian), Lovejoy, Prof. Frink, etc., I would assume to have middle names, but can’t think of any more names for the life of me.
Checking Wikipedia is for losers. Although I guess memorizing Simpson character names is for bigger losers.
Anyway, Skinner’s… err, Tamzarian’s… um… the principal of Springfield Elementary is W. Seymour Skinner. They made Seymour his middle name to make him a potential suspect for shooting Mr. Burns.
Bart and Lisa’s middle names come from a Simpsons family guide or something. I’m pretty sure neither has been used on screen.
And there’s my favorite, Robert Underdunk Terwilliger.
Marge’s full name is Marjorie, not Margaret.
Sideshow Bob is Robert Underdunk Terwilliger. That’s all I have to contribute.
Krusty’s full name is Herschel Schmoikel Krustofsky, and Professor Frink is John I.Q. Neidelbaum Frink Jr.
Okay, THAT one I only know from Wikipedia.
Lisa Marie was on the wedding announcement when she almost married Hugh.
Obviously a nod to Elvis’s daughter.
Is she really named Simpson? If so, explain! 
Dr. Eleanor Abernathy, M.D., J.D… AKA; Crazy Cat Lady.
[del]Isn’t there supposed to be a Nahasapeemapetilon in there somewhere?[/del]
Never mind.
[del]
No, she refused to marry him because her name was already too long. But I always thought it was very funny that Stu is apparently Disco Stu’s real last name, and that Selma married Lionel Hutz and re-married Sideshow Bob (!) “off-camera.”[/del]
[del]D’oh[/del]
Jasper Beardly, one of my favorite characters. I think they only revealed his last name recently, AFAIK.
Rainier Luftwaffe Wolfcastle, as we learned at his Homer-crashed-as-papparazo wedding.
I love that name. Fits him to a tee.
Carl Carlson and Lenny Leonard. Although Carl Leonard and Lenny Carlson would have been funnier.
Looking at the wikipedia article, I was surprised to see that Groundskeeper Willie has no last name. He seems like the biggest character on the show to not have a full name (unless his name actually is Groundskeeper Willie and Willie’s his last name).
“Willie” would be a humiliating last name for him to have. Think of all the undignified jokes he’d have to put up with.
His real last name is Johnson.
Made that up, btw.
The Sea Captain’s name was revealed as Horatio McCallister after the show had been on for quite some time. I had to look that up, for some reason I thought it was Archibald, although I remember vaguely the episode he was named in.
That was in his first appearance, actually (“New Kid on the Block,” season 4). It’s surprising sometimes how late some of those supporting characters were introduced.
But it would be a great pop-culture reference. Gilligan’s first name (never mentioned in the show itself) was Willie.
I don’t think it would translate as a Gilligan’s Island joke, but… hmm… I was going to say that his last name can’t be Willie because Skinner has called him William on at least one occasion. But he could be Groundskeeper William Willie.
For a long time there was fan speculation (corroborated by the noncanonical Simpsons comic books, IIRC) that Comic Book Guy’s real name was Louis Lane, but they finally gave him some totally blah name onscreen. Too bad. Louis Lane would have been perfect.
Given Millhouse’s and Wolfcastle’s middle names, they probably ought to give that Asian realtor the middle name “Hirohito” or “Tojo.”