It could be fire - breathing dragons. Given Naruto's own energetic and passionate nature, fire - breathing dragons would be a fitting match. They could add a new level of destructive power to his arsenal.
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.
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.
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.
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.
Sure. Fanfiction gives a lot of creative freedom. Some fanfic authors might come up with special circumstances or new abilities that enable Naruto to summon the Kyuubi. Maybe he discovers a hidden jutsu or makes a pact in the fan - made - up world of the story. This can make for really interesting reads as it twists the original Naruto story in unexpected ways.
In some fanfictions, Naruto might gain the ability to summon zombies through dark magic or a forbidden jutsu he discovers. Maybe he stumbles upon an ancient scroll that teaches him this unorthodox summoning technique.
A giant, hulking beast - type duel monster could also be very powerful. It might have incredible strength and endurance, able to take on multiple enemies at once. Its sheer physical presence could intimidate opponents, and it could use its brute force to smash through defenses and deal massive damage.
The rabbit summon could make Naruto more empathetic. If the rabbit is weak or in trouble when first summoned, Naruto would have to care for it. This would teach him to be more gentle and understanding.
Well, the cobra summon might introduce Naruto to a different style of combat. This could lead to him becoming more versatile in battle. He might learn new ways of using chakra from the cobra, which in turn could boost his confidence and make him more self - assured as a ninja. For example, if the cobra has a unique way of channeling chakra for its venom attacks, Naruto could adapt that into his own fighting style. Also, having the cobra as a summon could give Naruto a sense of responsibility towards another being, which would further mature his character.