Describe Magwitch in Great Expectations and say what his name suggests. (Chapter 40)

The convict whom Pip encounters on the marshes in the first chapter, Abel Magwitch has been the victim of the "prison of  society" that Dickens frequently castigates in his novels.  Born into poverty, in Chapter 40 of "Great Expectations" Magwitch answers Pip's question of "What were you brought up to be" by saying, "A warmit, dear boy."  Later, as he eats with his knife, he tells Pip,

I'm a heavy grubber...if it had  been in my constitution to be a lighter grubber, I might 'a got into lighter trouble.

As a child of the streets of London, Magwitch became a "varmit,"  feeding off whatever he could find, stealing from people, like a maggot--a fly larvae living on decaying matter. Used by Compeyson in his dastardly plot to rob Miss Havisham of her wealth and joy, Abel is the victim of evil, much like his Biblical namesake. 

That Magwitch wants to be known as Provis indicates his desire to change his misfortune, caused by the "witch" of Fate, to the good as he provides for Pip's better existence is evident.  On the other hand, he himself is a type of witch (a magic witch), an instrument of Fate, effecting the change of Pip's fortunes, both in positive ways--the money--and negatively--the disappointment of a convict as he benefactor rather than one of the upperclass.