Definitely Pikachu. Since Naruto is often in need of a quick and agile ally, Pikachu's speed and electric attacks would be very useful. Plus, Pikachu's cute appearance but powerful abilities would create an interesting contrast with Naruto's ninja style.
Naruto's character could develop a new sense of curiosity. Summoning Pokemon would expose him to a whole new world of creatures and powers. He might become more adaptable as he has to learn how to work with Pokemon, which have different personalities and abilities compared to the summons he's used to in his own world.
Well, in a Naruto can summon Pokemon fanfiction, it could work if there was some sort of cross - dimensional magic. Maybe Naruto discovers a hidden jutsu that allows him to open portals to the Pokemon world. Then he could start summoning Pokemon based on his chakra and willpower. For example, he might summon Pikachu if he needed a quick burst of electricity in a battle.
Another aspect is the character development. Naruto having Pokemon summons can change his relationships with other characters. His friends might be both amazed and a bit jealous. And he has to learn how to be a good 'trainer' as well as a ninja. This adds new layers to his character as he adapts to this new ability and the responsibilities that come with it.
Well, it depends on the specific fanfiction. There are countless Naruto fanfictions out there, and while some might depict Naruto as secretly a summon, others may not touch on this idea at all. It's all about the creativity of the fanfiction authors.
There's also 'Pokemon in the Naruto World: Summoned'. In this fanfiction, Naruto discovers a strange jutsu that allows him to summon Pokemon. The story then delves into how he uses these Pokemon to his advantage against his enemies, and how the presence of Pokemon changes the dynamics of the Naruto universe. It has great character development for Naruto as he learns to work with his new Pokemon partners.
In some Naruto fanfictions, it's possible for Naruto to summon snakes. Fanfiction often takes creative liberties, so writers might give Naruto this ability for the sake of an interesting plot twist or a new power - up. It allows for different storylines to develop, like Naruto using snake - based jutsus or having a connection to snake - related elements in the Naruto universe that he doesn't have in the original series.
One interesting storyline could be a young ninja who discovers a rare and powerful insect summon. For example, they might find a group of glowing beetles that can create illusions. The ninja then has to learn how to control and use these beetles in battles against other powerful foes in the Naruto universe.
He could summon different kinds of tigers. Maybe there are snow tigers for cold environments. These tigers would be white - furred and well - adapted to snowy areas. They could be used in missions in the Land of Snow.
Maybe Jiraiya. Since Jiraiya was Naruto's mentor and taught him a lot of things. He might have some knowledge about summoning kami and pass it on to Naruto.