Well, perhaps in this fanfiction, Harry Potter stumbles upon a lost baby in the wizarding world. He might then take it upon himself to find the baby's parents. Maybe he uses his magical skills, like casting spells to track the family. He could also seek help from his friends at Hogwarts, like Hermione who would surely be resourceful in finding clues about the baby's identity.
In this fanfiction, Harry Potter finding a baby could also lead to a whole new adventure related to the history of the wizarding world. Maybe the baby is related to a long - lost magical family or a forgotten part of Hogwarts' past. Harry would then be on a journey to discover the truth about the baby's origin, which could involve exploring old tombs, reading ancient books in the Hogwarts library, and even facing some dangerous magical creatures along the way.
Maybe the baby is a result of some sort of magical experiment gone wrong. And Harry Potter finds it in a hidden place where the experiment was carried out. The baby might have some strange and unpredictable magical abilities as a consequence.
One possible plot could be that Harry stumbles upon the Sword of Gryffindor in a hidden chamber in the Forbidden Forest. Maybe he's on a solo quest to find a powerful weapon against Voldemort and the magic of the forest guides him to it. Then he has to figure out how to use its power to his advantage in the upcoming battles.
The snake could be an injured or lost magical creature. Harry, being the kind - hearted person he is, decides to take care of it. As he does, he realizes that the snake has a connection to a powerful wizard or witch who has been lost for ages. This connection then draws Harry into an adventure to find out what really happened to that powerful figure and how it affects the present state of the wizarding world.
Well, perhaps in this fanfiction, Harry Potter stumbles upon a baby while on one of his adventures. Maybe the baby has some sort of magical power that he has to protect from the dark forces. It could also be that the baby is related to an old prophecy and Harry has to figure out how to keep it safe and fulfill the prophecy at the same time.
Well, perhaps Harry uses his magic to sense the One Ring's power. He might initially mistake it for a dark magical artifact from his own world. Then, he could start on a journey to figure out what this strange ring is, all while facing challenges from both the wizarding world (like Voldemort's followers thinking he has a new powerful weapon) and from Middle - earth forces that are also after the ring.
The plot could be that the cat is a magical key to a hidden chamber. As a child, Harry stumbles upon the cat and realizes it has a strange mark. When he touches the mark, it reveals a map that leads him to a secret chamber filled with ancient magic and knowledge.
Perhaps Harry is transported to a different dimension where the Power Rangers exist. There, he discovers the Wolf Zord. He has to learn how to bond with it, just like the Rangers do. He could bring some of his magic skills to the table, and in turn, the Wolf Zord gives him new abilities to use against Voldemort or other foes back in his own world.
It could be about Harry Potter somehow being transported to the Avatar world. Maybe he discovers he has bending abilities and has to learn to control them while also dealing with the political and social issues in the Avatar universe.
Well, it could be that the fog battleship is from a different magical realm. Harry stumbles upon it during one of his adventures outside of Hogwarts. Maybe the battleship is on a secret mission and Harry gets involved, using his magic to help them out against some dark magical forces that are after the ship.
Maybe Harry is sent on a mission by Dumbledore. Dumbledore has received some strange prophecies that seem to be related to Atlantis. Harry, along with his friends Hermione and Ron, travel to Atlantis. Once there, they find that the magic in Atlantis is different but related to their own. They have to figure out how to work with the Atlantean magic to stop an ancient evil that has been awakened and is endangering both Atlantis and the wizarding world. It could involve a lot of exploration of the Atlantean culture and magic system, which would be really fascinating.