Donald Zinkoff loves life and does everything with enthusiasm. He laughs uncontrollably at silly words—tintinnabulation, snickerdoodle, Jabip—and is generous toward others because he believes it will make them happy. He can be snippy at times, especially when he gets deeply involved in a project and someone tries to pull him away from it. Usually, though, he cooperates in his eccentric way. Donald loves to eat, but he throws up several times a week because he was born with an inverted stomach valve. The doctors finally fix that, but no one can fix his clumsy sloppiness and general incompetence. Donald finally comes to terms with his goofiness and stops trying to impress others or win their friendship. Instead, he simply loves the adventure of life and continues to share his enthusiasm and kindness with others.

Endlessly patient and loving toward her son, Mrs. Zinkoff awards him with stick-on silver stars for good days and tolerates his kitchen experiments. She is also capable of disciplining Donald, sending him to bed if he laughs continuously during dinner. She doesn’t quite understand her son—nobody does, not even Donald—but her love and patience helps him thrive despite his oddball behavior.