One possible plot is that the female basilisk is not like the traditional basilisks. She has a more gentle nature. Harry discovers her and they start to communicate through some kind of magic. They then go on a journey together to find a hidden magical artifact that can save Hogwarts from a new danger.
Well, in a non - adult way, perhaps the plot could be about Harry befriending a female basilisk in a magical forest. They might form an unlikely alliance against a common dark magic threat. Harry could use his unique skills and the basilisk's natural abilities to overcome challenges.
A plot could involve the female basilisk being an outcast in the magical world of basilisks because of her different views. Harry meets her by accident in a secret part of Hogwarts. They team up and Harry helps her gain acceptance among other magical creatures while she uses her basilisk - related powers to protect Harry from some evil wizards who are after him.
Perhaps in the fanfiction, the Basilisk has a hidden power that can only be unlocked by Harry's wand. A prophecy states that Harry must use his wand to unlock this power and use it for good. However, there are those who want to use the Basilisk's power for evil. Harry has to race against time to figure out how to use his wand to unlock the power and keep it out of the wrong hands. This would involve a lot of exploration of the Hogwarts secrets and battles against dark forces.
In a 'harry is a basilisk animagus fanfiction', the plot could involve Harry being an accidental basilisk animagus. At first, he's scared of his new form. But as he learns to control it, he uses it to his advantage. For instance, he might use his basilisk form to scare off Death Eaters or to find out secrets in the Forbidden Forest. He would also have to deal with the prejudice that comes with being associated with a basilisk.
I'm not sure about its popularity precisely. While the Harry Potter fandom is huge, this particular combination of Harry and Basilisk in a 'lemon' context might be more of a niche interest. Some people might be put off by the idea as it goes against the more traditional interpretations of the story. But on the other hand, there are always those who like to explore strange and unexpected pairings in fanfiction, so it could have a small but dedicated following.
Well, perhaps Harry discovers a basilisk egg in some hidden part of Hogwarts. He decides to hatch it out of curiosity or maybe because he believes it could be used to fight against the real threat in the wizarding world. He secretly takes care of it, using his magic knowledge to create the right environment for the egg to hatch.
One possible plot could be that Harry discovers a baby basilisk in the Forbidden Forest. He decides to take it in and raise it secretly. As it grows, he has to figure out how to control its deadly gaze and use its powers for good. Maybe he uses it to protect Hogwarts from dark wizards.
One possible plot could be that Fem Harry is targeted by a dark wizard who wants to use her as a weapon in her basilisk form. She has to fight against this control while also trying to find a way to reverse the transformation. Along the way, she might discover new powers or abilities that come with being a basilisk, and use them to her advantage in her fight for freedom.
Well, it could be that Harry uses his Parseltongue ability to communicate with the basilisk. Maybe he convinces it that he means no harm and that they can co - exist peacefully in Hogwarts. He might offer it some sort of deal, like protecting it from those who would want to kill it just because it's a basilisk.
A great plot idea could be that the female basilisk is actually a guardian of an ancient wizarding secret. Harry stumbles upon her while exploring a hidden part of Hogwarts. Instead of fighting, they form an alliance to protect the secret from dark wizards who are also seeking it. This would focus on mystery, adventure and cooperation rather than any inappropriate themes.
In this fanfiction, the Basilisk might be accidentally awakened near a magically - created nuke. The Basilisk's presence causes some sort of magical reaction that starts to set off the nuke. Harry, Hermione, and Ron are then on a race against time. They first have to find a way to calm the Basilisk, which is no easy feat as it's a giant and deadly serpent. Then they need to figure out how to defuse the nuke. This could involve using a combination of Hermione's vast knowledge of magic, Ron's loyalty and courage, and Harry's unique skills as the chosen one.
One plot idea could be that the male basilisk is actually a cursed wizard who can only take the form of a basilisk. Harry discovers this and tries to find a way to break the curse. Another could be that the basilisk has a special power that can help Harry in his fight against Voldemort, so they form an alliance.