Happy from Fairy Tail and Pinkie Pie from My Little Pony. Happy is a fun - loving and friendly cat - like creature, and Pinkie Pie is the life of the party. They would likely find each other immediately and start having a great time together, sharing jokes and treats. Pinkie Pie might even teach Happy some of her party - planning skills.
Gray is another candidate. Gray's cool and collected demeanor could contrast with Tobi's more mysterious nature. They could get into arguments about the best way to handle a situation, like when facing a powerful enemy. Or, they could find common ground in their skills and work together to protect Fairy Tail from danger.
Natsu would be a likely candidate. He's always up for a challenge and not afraid to take on powerful opponents. He'd probably be the first to rush towards Godzilla, either to fight it or try to befriend it in his own Natsu - like way.
Well, Lucy would be likely to interact with Naruto. She's friendly and curious, so she'd probably be one of the first to approach Naruto and try to understand where he came from. Gray is also a candidate. His cool - headedness (pun intended) would contrast with Naruto's more energetic personality. And of course, Makarov, the guild master. He would be interested in Naruto's abilities and might offer him a place in the guild or give him some tasks to prove himself in the Fairy Tail world.
The interactions could be really interesting. Goku's straightforward and somewhat naive personality in the face of new things would contrast with the more complex relationships and personalities in Fairy Tail. For instance, when he meets Mirajane, she would probably be very kind to him, offering him food and a place to stay at the guild. Goku would then repay her kindness by helping out with any threats that come the guild's way. And with Happy, Goku would find his flying ability really cool and might even try to learn how to fly in the same way, which would be a comical scene.
Well, if we think about it, Thor is a very proud and strong warrior. He might initially look down on some of the younger Fairy Tail members, thinking they are weak. But when he sees their determination and the unique magic they possess, he'd start to respect them. For instance, when he sees Lucy summon her celestial spirits, he'd be intrigued as it's a different form of power compared to his.
Natsu would be a very likely character. Since he and Lucy are close friends in the original story, if Lucy travels back in time, Natsu might be one of the first people she seeks out. They could have adventures together in the past, with Natsu being his usual impulsive self and Lucy having to keep him in check with her knowledge of the future.
Gray would be one of the main characters to interact with Natsu. Their friendly rivalry is well - known in Fairy Tail. Makarov, as the guild master, would also have an important role in interacting with Natsu. He might give Natsu some important tasks or just have a grandfatherly chat with him about his return.
The characters would interact in many interesting ways. Natsu, being hot - headed, might challenge Link to a fight at first. But then they could realize they are on the same side against a common enemy. Lucy would probably be fascinated by the magic and technology in the Zelda world and try to learn more about it. Zelda, on the other hand, could be intrigued by the Fairy Tail mages' powers and their guild system. She might see it as a way to better protect her own world.
Naruto would probably be really excited to meet the Fairy Tail characters. He's a friendly and outgoing person, so he'd quickly try to make friends. With his Rinnegan, he might be able to sense the different levels of power among the wizards and be in awe of some of their magic. The Fairy Tail characters, on the other hand, would be curious about Naruto. Natsu might challenge him to a friendly fight at first, thinking he's just another tough guy. Lucy would probably be more cautious and ask a lot of questions about where he came from and what the Rinnegan is.
The fire - based abilities of Natsu from Fairy Tail and the ice - based abilities of Hitsugaya from Bleach could create some really cool interactions. Natsu's heat might be able to counteract Hitsugaya's ice in an interesting way, like when they fight together against a powerful foe. Their different combat styles, with Natsu's more brute - force approach and Hitsugaya's more calculated and precise strikes, could also make for an exciting combination.