Dill does not have a pleasant home life. His mother seems to ignore him, especially when she remarries. His father is out of the picture. Dill therefore makes up a lot of things about his father, to fill in the gaps and make up for the pain he feels from not really knowing anything about his father.
In chapter 4, Dill is proud of the fact that he rode the train. When Dill arrives, he says he has “seen his father.”
Dill's father was taller than ours, he had a black beard (pointed), and was president of the L & N Railroad. (ch 4)
Of course, this is just another whopper. Dill tells these stories because the truth is too depressing. The Finch children know they are not true, of course, but they usually accept them because they realize that Dill’s not having a father is a big deal to him. Jem’s only response is when Dill says he helped engineer and Jem replies, “In a pig's ear you did, Dill” (ch 4). He tries to protect Dill by not pressing him and asking him any questions about his father.
As was mentioned in the previous post, Dill is highly sensitive about not having a father and continually lies to Jem and Scout in order to make himself feel better about his situation. Dill is also notorious for lying and has a wild imagination which influences his many unrealistic tales. In Chapter 4, Dill arrives from Meridian in a "blaze of glory." Dill immediately tells Jem and Scout that he met his father, who happened to be taller than Atticus, had a black beard, and was president of the L & N Railroad. Dill even claims that he was allowed to engineer the train for a while. Of course, Jem and Scout know that he is lying. Dill makes up stories so that he doesn't feel inadequate about not having a father like Jem and Scout. The Finch children understand Dill's unfortunate situation and do not give him a hard time about it. Later on in the novel, Dill forgets his story about his father having a dark, pointed beard and Scout catches Dill in his lie.