Symbolism, Imagery, Allegory
In Bud, Not Buddy, after Bud runs away, he needs a place to sleep, so he checks out the library. No go: it's locked up. Bud thinks: "… I was too tired to think anymore so I closed my suitcase, put the proper knots back in the twine, crawled under the Christmas tree and wrapped myself in the blanket" (5.55). That makes Bud a sort of like a Christmas present, see? Kind of funny, huh?
But it's not just a funny detail. Why would Bud be a Christmas present? Who is he a present for? His dad? His new family? Someone else?
Maybe Bud is like a gift because he has gifts inside just waiting to be discovered. Bud's momma did say that he was "waiting for just the right warmth and care to open up" (5.42), so a flower opening is like a gift you have to wait for: you can't appreciate it's beauty until it's finally ready to open. In that way, we could see Bud, Not Buddy as the story of Bud discovering his own gifts, with the help of the kind people he meets along the way. Bud is a good kid with good things to offer the people who care about him.
Even Miss Thomas, who barely knows him, sees that Bud is special. She tells him that even if things get tough, "…Something tells me that you were a godsend to us, you keep that in mind all of the time, OK?" (16.62) A "godsend" is another way of saying gift. Know what's even better? Bud is a surprise gift for Mr. C, who was not expecting to get a grandson out of the blue. How's that for a good present?