Ignatius J. Reilly, of course.
That’s who I thought of too, just couldn’t remember the name.
Yeah, that’s a good one!
Wouldn’t Zaphod Beeblebrox be more of the wild gesticulater than Arthur?
Maybe the OP is secretly envisioning Gandalf from Ralph Bakshi’s Lord of the Rings?
Concur.
Although, technically, I believe Kermit “flails.”
Broud from Clan of the Cave Bear.
No. Zaphod is smooth. Stupid as a sock full of gravel, but smooth, and rarely agitated. He’s definitely a gesticulator, but it’s broad, grandiose motions, not wild flailing.
Arthur, on the other hand, spends at least 3/5 books in the sort of highly agitated state that leads to wild gesticulations.
Ha! Same here. He’s even got the appropriate theme music to accompany wild gesticulation.
Sherlock Holmes while in disguise? 
Andrew Marr…
Non, m’sieur. I bring evidence. Poirot can be seen gesticulating as he runs down the street near the end of Mysterious Affair at Styles after he finds the important clue to the murder. His extravagant on-street gestures have embarrassed Hastings in other novels as well.
Thank you. And I am sure librarian dopers can attest that an MLIS degree attracts some pretty dumb people – this despite interesting theoretical research done in the field. Librarians, in general, don’t read, don’t watch, don’t know, don’t care.
There are exceptions, but there just isn’t a place in our world for curators of books.
First name that popped into my mind, too. For the life of me, I don’t remember any specific instances in Confederacy of Dunces (I read it once nearly ten years ago) where he gesticulates wildly, but his character was the first that came to me.
It makes me think of the character Jamie in the musical “The Last Five Years”, mostly because of the song “A Miracle Would Happen”, with the lyrics “And I’m showing her my left hand/I’m gesticulating with my left hand” to show this woman who’s coming on to him his wedding ring.
Thank you for defending my case, you put it better than I could have.
Swear to Og it really fits – Hitler!
Cheetah – Tarzan’s pal, who it turns out died just a few months ago at age 80.
Willy Wonka–in the BOOKS, not the movies–is a manic old man who I am sure gesticulated wildly.