One of the pranks Naruto might do is to mess with the Anbu's communication system. He could use his knowledge of chakra and some basic electronics (if we assume some modern - like elements in the fanfiction) to scramble their signals. This would make it difficult for them to coordinate with each other, and they'd be running around trying to figure out what's wrong while Naruto watches from a hiding place, having a great laugh.
In this fanfiction, Naruto might use his shadow clones to create chaos at the Anbu headquarters. He could make it seem like there are intruders everywhere, causing the Anbu to go on high alert and run around in confusion. Maybe he'll also replace some important documents with funny pictures or put whoopee cushions on their chairs.
In the fanfiction, Naruto might prank the Anbu by replacing their normal kunai with ones that make really loud and embarrassing noises when thrown. So when they go to use their weapons in a serious situation, they end up looking foolish as these noisy kunai fly through the air.
The main character is Naruto for sure. When it comes to the Anbu, there could be some new and original Anbu characters created just for this fanfiction. They could have unique abilities and personalities. Naruto's relationship with these made - up Anbu characters could be really interesting. He might prank them in ways that play off of their individual quirks. For example, if one Anbu is really proud of his speed, Naruto could set up a prank that makes it seem like he's much slower than he thinks.
One of the funniest pranks could be that the Kyuubi makes Naruto's clones start singing cheesy pop songs instead of following his commands. Naruto often uses his clones in battles and for various tasks. So when he sends them to attack an enemy, they all start singing and dancing instead. This would not only be a shock to Naruto but also to his opponents. Another great prank would be the Kyuubi making Naruto's body move in the opposite direction of what he wants. So when he tries to jump forward, he jumps backward instead, leading to all sorts of comical situations.
Naruto's adaptation to the Anbu in this fanfiction could be a complex process. At first, he'd probably struggle with the strict discipline and the need for secrecy. But his previous experiences in tough situations would come in handy. He'd gradually understand the importance of stealth and how to use his skills in a more covert way. He might also learn from the more experienced Anbu members, and his own determination would drive him to become a valuable part of the Anbu.
Naruto could enlist the help of his friends like Shikamaru. Shikamaru could come up with a really elaborate plan. For example, they could set up a fake mission where Ibiki thinks he's in charge, but it's all just a setup for a series of pranks. They could have actors pretending to be enemy ninjas who act really silly instead of being threatening. And Naruto could keep popping up in unexpected places during this 'mission' to further annoy Ibiki.
In a Naruto pranks Hyuuga fanfiction, Naruto might use his typical mischievous tactics. For example, he could use his shadow clone jutsu to create chaos around the Hyuuga compound. Maybe he'd make clones that pretend to be important visitors and then act all silly to embarrass the Hyuuga. It would be a really funny scenario as the serious Hyuuga clan tries to deal with Naruto's antics.
Some of the more hot - headed ANBU members might overreact and assume Naruto is a threat to the village. They could try to use force to get the stolen item back. However, the more level - headed ones might try to figure out Naruto's motives first. They might consider that Naruto could have a good reason for what he did, like if he thought the item was being misused by the ANBU.
One interesting storyline could be Sakura joining the Anbu and having to prove herself among the male - dominated group. She might face challenges like secrecy requirements and intense training, all while Naruto is on his own journey, and their paths cross in unexpected ways during missions.