Mockingbirds in To Kill a Mockingbird?

There are no litteral mockingbirds in To Kill A Mocking Bird, only metaphorical ones.

If you want metaphorical mockingbirds (characters that do no harm in the book), that would include:

Boo Radley

Miss Maudie

Atticus

Walter Cunningham Jr.*

Little Chuck Little

Tom Robinson

Calpurnia

even Scout's dead mother fits here....

*questionable