One idea could be exploring how the other monsters react to Ginormica's pregnancy. Maybe they're excited and start preparing for the new arrival in their own wacky ways. For example, B.O.B. could try to make baby toys out of his gooey substance, but they keep turning into strange shapes.
A possible storyline could involve the challenges Ginormica faces during her pregnancy in a world full of monsters and aliens. She might have to deal with unusual cravings that are specific to the Monster vs Aliens universe, like a craving for the energy crystals that power the alien technology. And she has to figure out how to keep herself and the baby safe from potential alien threats.
Perhaps the pregnancy is not a normal biological process. Instead, it's a result of some alien experiment gone wrong. Ginormica has to figure out how to reverse the process or come to terms with the fact that her baby might be something entirely unexpected. This could lead to a lot of self - discovery and moral dilemmas for her.
In a fanfiction, the aliens could capture Naruto and try to study his unique abilities. The monsters then decide to rescue him because they realize his powers could be the key to defeating the aliens once and for all. The story could involve a lot of action as the monsters infiltrate the alien base to save Naruto.
One plot idea could be that aliens invade the Naruto world seeking a powerful energy source, which is actually the chakra. The Naruto monsters then team up to defend their world. Another could be a group of Naruto monsters getting accidentally transported to an alien planet and having to fight their way back home. They could learn new techniques from the aliens they encounter during their journey.
One idea could be a story where the monsters and aliens have to team up against an even greater threat from another dimension. Maybe a powerful interdimensional being that wants to conquer both Earth and the alien planets.
A third possibility is that the pregnancy has some sort of magical or unexpected origin. Maybe it was a result of a unique event, like a comet passing overhead that had some sort of strange effect on them. This leads to the pregnancy, and as it progresses, Esme starts to develop new powers or abilities. Carlisle is both fascinated and concerned, and they both have to figure out how to handle these new developments while also ensuring the safety of their unborn child.
One idea could be that they accidentally find out they're expecting during a mission together. Maybe they had a one - time moment of closeness before and now have to deal with the unexpected pregnancy. This could lead to a lot of drama as they both have important roles in their village and their relationship has always been complex.
Perhaps the OC is initially distrusted by Susan and the other characters. But as the story progresses, through various adventures and challenges, like facing a powerful alien invader, the OC proves their worth and they form a strong bond with Susan. They might have to combine their unique skills, Susan's size - changing ability and the OC's special weapon or power, to defeat the enemy.
One idea could be exploring how Simba reacts to the news. He might be overjoyed and start making preparations for the new cub right away. He could gather all the animals in the Pride Lands to share the good news and seek their support and blessings.
Power and its consequences is also a theme. The OC may have some special power, and the fanfiction explores what they do with it. They could use it for good, like helping the monsters protect the Earth, or it could lead them astray if they misuse it. This theme adds depth to the story and the character of the OC.
The plot involves a group of monsters coming together to fight against aliens. Susan becomes Ginormica and teams up with the likes of B.O.B, Dr. Cockroach, and The Missing Link to save the world from the alien threat.