A possible plot for 'pregnant Aku in Samurai Jack fanfiction' is that Aku's pregnancy is a sign of a greater threat to the world. It could be that the unborn entity within him has the potential to be even more powerful and evil. So, Aku has to decide whether to keep the pregnancy for his own gain or try to get rid of it to prevent a greater catastrophe. At the same time, Jack might sense this new danger and start to investigate, leading to some tense encounters between them.
Well, a plot could revolve around Aku trying to keep his pregnancy a secret from Samurai Jack. He might be worried that Jack would use this new situation to his advantage. And then there could be a sub - plot about Aku having strange cravings that lead him to unexpected places in the world of the fanfiction, causing chaos in different ways.
The character of Aku could be developed in a 'pregnant Aku in Samurai Jack fanfiction' by exploring how he interacts with the world around him differently. He may become more reclusive as he doesn't want others to see his 'weak' state. Or he could become more aggressive in trying to protect his pregnancy, which would be a new aspect of his character. Also, his relationship with his own power might change. Maybe he has to find new ways to use his magic that don't harm the unborn, which would force him to grow and adapt in ways he hasn't before.
There could be a plot where the ninjas in the Naruto world are being influenced by Aku's dark magic. Samurai Jack, with his unwavering sense of justice, teams up with Naruto and his friends to break the spell. They then travel to Aku's lair to take on Aku directly. Another interesting idea is a world where the Naruto characters are re - imagined as samurai, and Jack has to train them in the ways of the samurai to face a new threat that combines the worst of both their worlds.
One idea could be creating an OC who is a long - lost relative of Samurai Jack. Maybe a cousin who has also been trained in the ways of the samurai and comes to help Jack in his fight against Aku. This OC could have unique abilities, like the power to control the elements, which would add new and exciting elements to the story.
Perhaps they find out about the pregnancy in a very unique way. For example, Miko has been feeling strange and Jack, being the observant one, takes her to the doctor. It turns out she's pregnant. Then they start a journey of preparing for the baby. They attend parenting classes together, read books on pregnancy and child - rearing, and slowly build their confidence as future parents.
Well, perhaps in the fanfiction, the pregnancy could be a catalyst for them to start thinking about their future more seriously. They might start planning a life together off the ship, looking for a place to settle down. It could also lead to some comical situations, like Jack trying to build a makeshift crib in their small cabin.
One plot idea could be Jack and Ashi exploring a new, uncharted land together. They face strange creatures and have to use their combined skills to survive. Another could be a story where they go back in time to prevent a certain event that would have a huge impact on their future. And a third idea is that they have to protect a magical artifact from an evil force, with their relationship growing stronger throughout the adventure.
It could be that Aku read stories to children as a way to exert control over their minds and influence their thoughts in his favor.
One idea could be a crossover where the characters from RWBY and Samurai Jack team up to fight a common enemy. Maybe a powerful Grimm has somehow made its way into Jack's world, and he needs the help of Ruby and her team to defeat it.
One idea could be the young samurai going on a journey to find a lost ancient sword. Along the way, he meets various characters who either help or hinder him.
One idea could be that Jack and Rapunzel are living in a small, peaceful village when they discover Rapunzel is pregnant. They then have to face the challenges of preparing for a new life together, like building a bigger home. Another could be that they are on a magical adventure while Rapunzel is pregnant, and they meet different magical creatures who offer their help and wisdom for the upcoming baby.