In chapter 1, Maniac Magee, during his school play, screamed, and then when everyone heard him, he just ran away with the clothes on his back. He never returned to his aunt and uncle or school.
In chapter 4, Jeffrey interrupted a football game. He ran onto the field, book in hand, and he caught the football with on hand. Then he punted it to the reciever who caught it perfectly.
In Chapter 6, the Pickwells were eating dinner. Maniac Magee just joined in. The kids finally realized that none of them knew him and that he had just "joined" the dinner all by himself. When he left, Maniac Magee ran on the steel rail itself!