Often, in these fanfictions, the wolf is portrayed as highly intelligent. It could communicate with Sherlock in its own way, not necessarily through words but through gestures and expressions. This allows for some really interesting interactions. There could be a story where the wolf gets lost in the city, and Sherlock has to search for it. During this search, he discovers new aspects of the city and new mysteries. The wolf's presence also adds an element of the wild to Sherlock's otherwise very urban and civilized world, creating a contrast that can be used to great effect in the storytelling.
Some stories might focus on the wolf's origin. Maybe it was a product of some strange experiment, and Sherlock is trying to figure out how it came to be. This could tie into his general interest in the unusual and scientific mysteries. Or the wolf could be from a far - off land and have some sort of magical or mystical abilities. In fanfiction, the possibilities are endless. Writers could also explore how the wolf interacts with the other characters like Watson. Watson might be initially afraid of the wolf but then grow to appreciate it as he sees how useful it can be in Sherlock's work.
One common storyline could be the wolf helping Sherlock in his investigations. Since wolves have a great sense of smell and are very perceptive, it could detect clues that Sherlock might miss. For example, it could lead him to a hidden location where a crucial piece of evidence is stashed. Another storyline might involve the wolf being in danger, and Sherlock having to use his detective skills to protect it. This could introduce some action - packed scenes as he fends off villains who want to harm the wolf. Also, the wolf could have a special bond with Sherlock that is explored, perhaps it was a gift from an old acquaintance, and its presence in Sherlock's life changes his perspective on certain things.
The wolf can also enhance Sherlock's sense of mystery. It's not a common pet, and people in the stories would be curious about it. This would draw more attention to Sherlock and his unique lifestyle. And when he is out with the wolf, it gives an impression of him being even more unpredictable. For example, if he takes the wolf on a case, it might startle the suspects or witnesses, and Sherlock can use this to his advantage. He can observe their reactions more closely when they are distracted by the wolf.
There could be fanfiction where Sherlock Holmes has a pet bird. The bird might be trained to carry small messages or act as a lookout. For example, it could alert Holmes when a suspect approaches his Baker Street residence. This would bring a unique element to the traditional Sherlock Holmes stories, as it combines the charm of having a pet with the mystery-solving aspect.
One popular storyline is where Moriarty fakes his death in a more elaborate way than in the movie. Writers might have Sherlock on a wild goose chase trying to prove Moriarty is truly alive. Another is Holmes and Watson getting into a dangerous adventure in a foreign land that was only hinted at in the movie. For example, they could be in a place like the Balkans, dealing with political intrigue and secret societies.
A common theme is family. Since they are siblings, fanfictions often explore their family bond, whether it's a strained relationship at first that gradually improves, or a strong bond from the start that they rely on during cases. For example, in some stories, Sherlock initially underestimates Enola but then realizes her value as a family member and detective.
Obviously, Sherlock Holmes is one of the main characters. And then, depending on the type of pet, the pet itself becomes a significant character. If it's a dog, the dog would be a central figure, perhaps named something like 'Scout' and be very loyal to Holmes.
A prevalent theme is the exploration of intelligence. Holmes' deductive reasoning is pitted against the ninja's instincts and knowledge. Also, friendship can be a common theme. Just as Naruto values his friends, Holmes might form new relationships in the Naruto universe. And there's often the theme of adaptation, as Holmes has to adapt to a world full of chakra and jutsus instead of the streets of London.
The theme of adaptation is quite common too. Sherlock Holmes has to adapt to the strange new world of Naruto, with its different rules, powers, and social structures. At the same time, Naruto characters might have to adapt to Sherlock's rather un - ninja - like ways of doing things. And there's also the theme of uncovering secrets. Sherlock's nature of uncovering hidden truths fits well with the Naruto world which is full of secrets, be it about the origin of certain jutsus or the true motives of some characters.
The theme of justice is also very common. Both Sherlock Holmes and Batman are dedicated to bringing criminals to justice. In fanfiction, they often team up or compete in the pursuit of this goal. They might have different ideas about what justice means exactly, but they both strive to make their respective worlds a better place by stopping the bad guys.
One common theme is mystery - solving. Just like in the original Sherlock Holmes stories, the fanfictions often have him using his deductive reasoning to solve magical mysteries in the Harry Potter world.
One common theme is mentorship. Often, Sherlock Holmes takes on the role of a mentor to the little girl, guiding her in the ways of deduction and mystery - solving.