What could happen when Harry Potter talks to the dragon in fanfiction?

Well, he might try to tame the dragon. In some fanfictions, Harry could use his magic skills to communicate with the dragon on a deeper level, perhaps to gain its trust and make it an ally.

In some fanfictions, Harry Potter might learn some hidden secrets about the wizarding world's economy from the goblins. The goblins are known for their control over Gringotts and have a deep understanding of magical treasures. Harry could discover a new plot against Hogwarts related to a valuable artifact hidden in the vaults.

Well, he might be really confused at first. Fanfiction often takes the original story in different and sometimes wild directions. He could be shocked to see how some fans have imagined his relationships or new adventures that are quite different from his own experiences.

Well, he might be tempted by the dark magic within the Horcrux. It could try to manipulate him, maybe show him false visions of power or ways to defeat Voldemort that are actually leading him astray.

Maybe Harry discovers a new type of snake with magical abilities. For example, it could be a snake that can turn invisible at will. This would be really cool as it could add a new dimension to the wizarding world's magical creatures.

Maybe Harry tries to reason with the troll. He could use his magic skills to calm the troll down and prevent it from causing more chaos.

Well, in the fanfiction, Harry might seek Merlin's advice on dealing with dark magic threats. Merlin, being an ancient and powerful wizard, could offer unique insights that help Harry in his battles.

In some fanfictions, Harry might seek Snape's advice on how to deal with the remaining dark magic threats. Since Snape was so knowledgeable, his portrait could offer unique insights.

Well, it could be about Harry seeking the dragon's help to find a hidden magical item. Maybe the dragon knows the location of an ancient artifact that can defeat a dark wizard. So Harry has to communicate with the dragon, overcome his fear first, and then persuade it to share the secret.

One interesting scenario could be Harry having a conversation with the Whomping Willow. He could find out why it's so aggressive and maybe even convince it to be more friendly. Another could be him chatting with the house - elves through the rats or other small animals that might be in the kitchen. He could learn more about their secret world and their hopes and dreams.