Maybe Harry somehow ends up in the Naruto world and decides to take Naruto under his wing. He could teach Naruto about the value of friendship in a different way than Naruto's friends do. Harry has experienced a lot of loss and betrayal, so he could share his wisdom on how to deal with difficult emotions while still being true to one's self. He might also introduce some of the magical items from his world to Naruto, like the invisibility cloak which could be used in a really interesting way during Naruto's ninja missions.
One possible plot could be that Harry, using his magic skills, protects Naruto from the various threats in the Naruto universe. For example, he could use spells to shield Naruto from enemy ninjas' attacks. He might also use his knowledge of magic to help Naruto understand some concepts that are difficult in the ninja world, like a different way of looking at chakra manipulation which could be related to how magic works in Harry's world.
Well, maybe Harry discovers an injured snake in the Forbidden Forest. He decides to take it back to the Gryffindor common room and hides it in his trunk. He uses his magic to heal the snake and then starts to feed it small magical creatures. Eventually, the snake becomes his secret pet and helps him out in some tricky situations, like warning him of approaching danger.
Maybe Harry discovers a baby snake in the Forbidden Forest and decides to take it under his wing. He could use his Parseltongue ability to communicate with it and keep it hidden from the other students and teachers.
One possible plot could be that Harry discovers a time - traveling accident has brought baby Snape to his present. Harry, being the kind - hearted person he is, takes it upon himself to care for the baby. He has to figure out how to feed the baby, keep him clean and comfortable. Maybe he also has to protect baby Snape from any threats in the wizarding world that might target Snape even as a baby.
One possible plot could be that after the death of Dumbledore and with the Order of the Phoenix in disarray, Harry decides to go into hiding alone. He uses his skills in magic, like the Patronus charm for protection and the Invisibility Cloak to avoid detection. He might start to forage for his own food in the Forbidden Forest, using magic to find edible plants and hunt small magical creatures in a humane way. He also spends his time studying advanced magic on his own to become stronger, preparing for the final battle against Voldemort.
One possibility could be that Draco is forced into taking care of Harry due to some magical circumstances. Maybe there's a spell gone wrong that makes it his responsibility. He initially resents it but as he spends time with baby Harry, he starts to see the innocence in him and develops a soft spot.
In one scenario, Anko could train Naruto in some unique jutsu that she has mastered. She might see his potential and take him under her wing to help him improve his combat skills faster.
Well, Naruto might be really confused at first. He's from a world of ninjas and suddenly has to take care of a baby wizard. He'd probably use his ninja skills to protect Harry. For example, he could set up traps around the house to keep bad guys away. And he'd surely try to feed Harry some ramen, which might be a bit strange for a baby used to wizard food.
Well, it could be about Snape feeling a sense of duty. Maybe after Harry loses his sight in a battle against the Dark Arts, Snape, despite their past differences, steps in. He might start by teaching Harry new ways to navigate Hogwarts using magic that doesn't rely on sight, like advanced sonar - like spells.
In the fanfiction, Naruto would be super protective. He'd use his ninja skills to keep the baby safe from any harm. For example, if there was a threat, he could quickly create a barrier around the baby using his chakra. Also, he'd be really patient, which is a bit different from his usual impulsive self when it comes to taking care of the baby.
Well, a great plot point could be Harry trying to figure out Draco's needs. Since he doesn't know much about taking care of a Malfoy baby, he has to learn quickly. He might discover that Draco has a particular preference for a certain type of lullaby or a soft blanket. Also, there could be a part where Draco gets sick. Harry would be really worried and would have to seek help from the magical world's healers. This could lead to some interesting interactions as he tries to keep Draco's identity as a Malfoy a secret to avoid any unwanted attention.