A great plot might be that Poseidon has to protect baby Percy from other mythological beings who sense his potential power. So he hides Percy in a special place where only he can find him. This could lead to all kinds of adventures as Poseidon has to fend off threats while keeping Percy's existence a secret.
Perhaps in the fanfiction, baby Percy has some sort of connection with the ocean even at a very young age. He might be able to communicate with sea creatures on a basic level. Poseidon could be guiding this connection from afar, and when Percy is in danger, the sea creatures come to his rescue. This would create a really unique and heart - warming story about the bond between Percy and Poseidon even when Percy is just a baby.
One possible plot could be Poseidon teaching Percy about his underwater powers in a really fun and father - son way. For example, they could have little adventures in the ocean where Poseidon shows Percy how to communicate with sea creatures. Another plot might involve Poseidon protecting Percy from the other gods who are jealous of Poseidon's special relationship with his son. Maybe he creates a hidden underwater lair for Percy to grow up safely.
One interesting plot could be Percy having to prove himself to Poseidon in a new and unexpected way. For example, he might have to solve a mystery that is directly related to Poseidon's power over the sea but in a realm that is unfamiliar to both of them, like an underwater civilization that has been lost for centuries.
In fanfictions, Poseidon often interacts with baby Percy in a very gentle and protective way. He might use his powers to create a safe environment for Percy, like a special underwater grotto where Percy can be hidden from danger. Sometimes, he sends sea creatures to watch over Percy, like dolphins or friendly sea nymphs.
The relationship could be shown as a curious one. Since Percy is a baby, he might not fully understand who Poseidon is, but there could be an instinctual bond. Poseidon, on the other hand, could be filled with a sense of wonder at this small version of his son, seeing all the potential in him. He might try to communicate with Percy in gentle, non - verbal ways, like sending small ripples of water to make Percy laugh.
Another plot could involve Percy discovering a hidden connection between Poseidon and Athena that was long forgotten. This could lead to a situation where he has to convince the other demigods that this connection is important for the future of the camp. Maybe there are ancient prophecies that only he can understand due to his unique parentage.
One interesting scenario could be Poseidon using his powers to create a mini - underwater world for baby Percy to explore safely. He might make colorful fish swim around Percy and gentle sea currents act like a cradle.
One idea could be Percy as a baby having small adventures in the underwater world of Poseidon. Maybe he befriends a baby sea monster. Another could be Poseidon trying to protect baby Percy from the other gods who are suspicious of this half - god baby.
Well, clearly Percy and Poseidon are the main characters. Percy, as a baby, is full of potential and mystery. And Poseidon, being his father, has a big role to play in protecting and guiding Percy.
A plot could also center around the baby's identity and how it fits into the existing world of Percy Jackson and the Olympians. The baby might be seen as a symbol of a new era, a bridge between different pantheons perhaps. And it could face difficulties in being accepted by both the mortal and the divine worlds.
In some versions, Poseidon might keep Percy's mother at a distance to protect her from the wrath of the other gods. He could send her gifts secretly to let her know that Percy is okay. For example, he might send a magical seashell that can communicate with Percy.