Which Characters from the Great Gatsby can fit the description of Flat, round, static, foil, stock, dynamic, and confidante?****why is this...

I think the flat role would really fit Tom pretty well. 
He is basically in there to be a boorish, nasty, racist bastard with tons of money.  You
don't get a more thorough look at him.

As a confidante,
Nick certainly fits the role, he is telling the story, treating the reader as a
confidante.

I think you could make the argument that Daisy
is static.  She maintains the constant role as a manipulator, no matter who she is
around, no matter who she is manipulating, she never relents and never changes her
tune.  She's used her beauty her whole life and she doesn't stray from that
path.