Although The Simpsons is itself a show mainly consisting of fictional character (see List of characters from The Simpsons), excluding celebrities who make cameos as themselves, there are a number of characters within the show's universe who are fictional to the Simpsons characters themselves.
These include characters from TV and movies, as well as characters who appear on Halloween "Treehouse of Horror" episodes, which do not fit the show's already-loose continuity.
The Angelica Button series parodies the Harry Potter series. The books were written by T.R. Francis (mirroring J.K. Rowling, who created the Potter series). It appeared in the episodes "The Haw-Hawed Couple", "Smoke on the Daughter", and "Once Upon a Time in Springfield".
Four titles of the books have been released in three episodes of The Simpsons:
Read more about Radioactive Man (The Simpsons) at Wikipedia ...
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