Complex sentence: Bart asks in a mock Cockney accent to have the day off school, with a pain in his "gulliver"-an allusion to the invented language used by characters in the book and film.
Split into simpler sentences: Bart asks in a mock Cockney accent to have the day off school, with a pain in his "gulliver". This is an allusion to the invented language used by several characters in the book and film.