What are some good symbols for some of the following characters in To Kill A Mockingbird: Scout, Dill, Boo, Atticus, Tom, Jem, Bob...

In To Kill A Mockingbird, Tom Robinson is an innocent man. He has been accused of a crime and now stands trial in a town where the people have their own sense of justice and a warped sense of right and wrong. As much as the people despise Bob Ewell, they accept his testimony against Tom on the grounds that he is white and Tom, as a black man, cannot be trusted or believed. Atticus points out,

"The witnesses for the State... have presented themselves ... in the cynical confidence that their testimony would not be doubted... An assumption that one associates with minds of their caliber, and which is, in itself, gentlemen, a lie..."

He continues with his arguments when he confirms that Tom is a "respectable Negro ...who has had to put his word against TWO white people's!" It is a sad truth and Atticus finishes by adding, "The defendant is not guilty - but somebody in this courtroom is" (chapter 20, page 207, 1988 edition).

Tom could be a punching bag or scapegoat (modern interpretation) as he must take the brunt of everyone else's shortcomings and pay for their obtuse and unacceptable disposition. He is like the Phoenix because, tragically, he will die, but his cause will not and the reader hopes that enough has happened to make Tom's death more meaningful. 

Atticus is a port in a storm and could be described as a Crane because Judge Taylor selects him to defend Tom because he knows he will do everything in his power to defend Tom and obtain a fair outcome, even though it is unlikely. Atticus can hold his head up high. Cranes are endangered as are people like Atticus. 

Bob Ewell could be a Crow because Crows are known to eat other smaller birds, have no allegiance and they find protection from other crows, so they are always in groups. Bob may not be liked by the townsfolk but he is safe in this community.  

Boo could be an Albatross which is sometimes considered a burden and can be a symbol of good and bad luck, depending on how it is treated. In The Rime of The Ancient Mariner, the mariner shoots at the albatross, previously considered to be a good luck indicator, after which the crew blame the mariner for their consistent bad luck. Birds make appropriate symbols for many of the characters in the novel and this reinforces Harper Lee's own use of bird symbols.