The lion could be from a hidden part of the Naruto world, a place that's full of exotic and powerful animals. Maybe Naruto discovers this place during one of his adventures and befriends the lion there.
Perhaps they go on an adventure to find a special kind of herb that can heal the sick in the village. The lion's keen sense of smell helps them track it down, and Naruto uses his ninja skills to fend off any threats that come their way during the search.
The pet lion could be a major plot changer. It could be a symbol of Naruto's growing power and status. Maybe the lion has some special abilities that help Naruto on his quests. For example, it could have the ability to track enemies or find hidden treasures. This would add a whole new dimension to the story.
Well, Naruto might have some training sessions with his pet tiger. The tiger could be a great sparring partner, teaching Naruto new combat skills or helping him improve his reflexes. They could also go on missions together, with the tiger using its natural abilities like stealth and speed to assist Naruto in completing the tasks.
The pet dinosaur could be from a hidden part of the Naruto world, perhaps a place where ancient and extinct creatures were preserved by some kind of powerful jutsu. Maybe it was discovered during one of Naruto's adventures, like in a deep, unexplored forest or a secret underground cave.
In a 'naruto has a pet dog' fanfiction, the dog could be a great companion during Naruto's training. It might be a stray that Naruto found and decided to take care of. The dog could have special abilities, like being able to sense danger or find hidden things. It could also be a source of comfort for Naruto when he's feeling down about his lack of progress or when he misses his friends.
Well, it could change a lot. For one, Naruto would have a super powerful ally. The dragon could help him in battles against tough enemies like Pain or Madara. It might also change how others in the village see him. Instead of just being the Jinchuriki of the Nine - Tails, he'd be the guy with a dragon too. This could lead to new adventures as he tries to figure out how to take care of the dragon and use its powers to protect the village.
The pet dinosaur could be a great asset in combat. It could use its size and strength to intimidate opponents or directly engage in battle. For example, it could charge at enemies, knocking them down with its powerful body.
Naruto's relationship with the pet fox could develop through shared adventures. For instance, when they are on a mission together. The fox might get injured, and Naruto would do everything he could to save it. This would strengthen their bond. Also, in quiet moments, they might just sit together and the fox would listen to Naruto's dreams and fears, becoming his most loyal confidant.