Nancy K. Stouffer

Nancy K. Stouffer, of Camp Hill, Pennsylvania, published a number of activity books in the 80's, including Larry Potter and his Best Friend Lilly and Rah and the Muggles, which exhibit many startling similarities to the incredibly popular Harry Potter series, which has led to numerous allegations of plagiarism, and lawsuits from both sides.
Stouffer claims a number of strange similarities, such as the character names (Larry Potter / Harry Potter, Lilly Potter / Lily Potter), the word Muggle, and certain settings and descriptions such as a castle on a mirrored lake - she details 44 in all on her website. Separately, no single similarity (except perhaps the word "Muggle") is enough to support her claims, however the large number of coincidences does appear to weigh in her favour. Despite this evidence something that Stouffer has been deliberately muddling is the fact that the similarities occur across several different unrelated stories in her books. Larry and Lilly Potter are not in anyway connected to the book about the Muggles. The stories about Larry and Lilly are just kids stories about a couple of friends, while the Muggle stories are post-holocaust fantasies about strange alien-looking mutants. Most other similarities she claims are simply too vague or common in the genre to be accepted.
Stouffer (who's name now appears on reprints of her books as "N.K. Stouffer" - disturbingly similar to J.K. Rowling, whom she accuses of imitating her!), claims significant losses and irrepairable damage to her original works, to the tune of millions of dollars. According to her attorney, Kevin Casey, her company was projecting earnings of $1 billion, from licensing agreements and pre-orders, but suddenly her company fell apart, and in the midst of copyright disputes, was unable to fill orders. All records of these transactions were lost when her house collapsed in the middle of a snowstorm. Despite this, and despite the inability to locate any original copy of her book when requested, Stouffer persists in pursuing monetary compensation for her alleged losses.
As of December 5, 2000, the case had not yet been dismissed, and Stouffer continues to "fight the good fight." She says that she is not jealous of Rowling's success, but simply seeks retribution for what she feels was stolen from her.