- Luna Lovegood. Originally to have importance only in Order of the Phoenix, by the end of the series she is the sixth member of the Harry Potter True Companions, and the only non-Gryffindor to be in it. Luna's so popular, she managed to make her Quibbler critters a popular source of Arbitrary Skepticism jokes in the fandom, and many fans were disappointed that she never discovers a Crumple-Horned Snorkack during her time as a Magizoologist.
- Draco Malfoy, who of course is given Draco in Leather Pants treatment.
- Blaise Zabini is only a name until the sixth book when he's at least given a gender and a race, but he has many appearances in fanfiction as a main character.
- Theodore Nott also has plenty of fans despite his few appearances and lack of lines. Part of this may be due to the fact that he was supposed to have a larger role.
- Neville Longbottom. He's a Memetic Badass for a reason.
- The Giant Squid is popular in crack fics and Wild Mass Guessing and the like.
- TGS was SO popular, JK herself had to put an end to mass rumour that it was actually Godric Gryffindor as a 1000-year-old animagus.
- It should be noted that all this is despite the fact that it appears three or four times in the entire series, serves almost exclusively as a source for jokes, and never impacts the plot at all.
- It eats one of Harry's unwanted pieces of toast in The Goblet of Fire.
- And saves Dennis Creevey!
- Albus Severus Potter. Largely because of what his initials spell, and considering that the Slytherin House is associated with snakes...
- Professor Minerva McGonagall gets this as well. Originally introduced as a typical Stern Teacher, thanks to her hilarious comments during Quidditch matches, loyalty to Dumbledore and Harry, especially in the fifth and seventh books, and a few stunning feats of magic during the Battle of Hogwarts, she became synonymous with Cool Old Lady.
- The Weasley Twins, Fred and George, mainly because they are the living example of Crowning Moment of Funny (which is also very necessary, as the books get so much darker as the series progressed).
- Fans just love Lucius Malfoy.
- Although Voldemort is the Big Bad, many fans Love to Hate Umbridge (and to a lesser extent, Bellatrix) even more than him.
- Snape, Snape, Severus Snape. It helps that he's played by Alan Rickman in the films, but even before that, he was already hugely popular among the readership. The Sadist Teacher and Red Herring suspect in the first book who seems to be trying to steal the Stone and kill Harry in the Quidditch game. When the truth turned out to be the opposite (he was trying to keep the real culprit from stealing the Stone and saved Harry's life in the Quidditch game) he became bizarrely fascinating. An outwardly nasty character who is working with the good guys, he introduced a shade of gray in what seemed at first glance to be a Black-and-White Morality series. With his devastatingly witty put-downs and his big black cloak, he became a Draco in Leather Pants to rival Draco, with the justification that he was seemingly a good guy. Then came the sixth book with the shocking plot twist that everyone now knows. It says much of his popularity, that for the seventh book, Scholastic put much of it's publicity around him with its "Snape: Hero or Villain?" debates, despite his minimal appearances in that book. Those appearances didn't disappoint, revealing a tragic backstory that explains (but not justifies) some of his nastiness, making him probably the biggest polarizing character in the series.
- Both Remus Lupin and Sirius Black are very popular characters amongst the fans, placing 6th and 5th respectively on this list of the greatest Harry Potter characters, behind only the Golden Trio and Snape.
- Mad-Eye Moody, wizard drill sergeant and badass good guy extraordinaire.
- Antonin Dolohov has his share of fans. Possibly due to being one of the more competent Death Eaters and almost always winning the duels he participates in.
- The fans are so crazy even characters who barely get mentioned at are, such as Daphne Greengrass, the Patil twins and Susan Bones, or not at all, are at times more popular then established characters over the time frame of several books, such as the Gryffindor Chasers, Cho Chang, or Justin Finch-Fletchey.
- Many characters who are deceased before the series even begins get this treatment. Some examples include Evan Rosier and Marlene McKinnon.
- Tonks. Fans absolutely love her, despite the fact that she doesn't appear until fifth book and is relatively minor character with only a few lines in the entire series.
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