One possible plot could be that the ogre babies fall ill due to a magic spell gone wrong in the swamp. The spell could have been cast by a vengeful fairy who was angry at Shrek for some reason. Shrek and Fiona then have to go on a journey to find the antidote to save their babies.
Maybe in the fanfiction, the ogre babies are kidnapped by an evil ogre tribe that wants to use them for some dark ritual. Shrek has to fight against his own kind to rescue his children. This could involve a lot of action scenes where Shrek uses his brute strength and Fiona uses her martial arts skills.
Perhaps it's a new character, like an evil wizard who has heard about the power of Shrek's family. He believes that by getting rid of the ogre babies, he can gain control over the swamp and all of Far Far Away. So he devises various evil plans to harm them.
One possible plot could be that the bear is a loner in the Shrek world. It sees all the other characters like Shrek, Donkey, and Fiona having their own groups and relationships. But the bear, due to its gruff appearance or different habits, is shunned. So it becomes sad, feeling like it has no one to belong to.
It depends. Some babies might enjoy the humor and characters in Shrek cartoons, but others might find it a bit overwhelming. It's best to start with short viewings to see how your baby reacts.
One possible plot could be that Harry is trapped in a magically sealed chamber with no food sources. As time passes, he slowly weakens due to starvation while trying to find a way out. Another could be that he's on the run from dark wizards who have somehow managed to cut off all his supply lines to food. Maybe they've cursed all the places he could get food from. It's a very dark take on the Harry Potter universe.
One possible plot could be that Naruto discovers a hidden conspiracy within the Forest of Death that led to him being left there. Maybe some rogue ninja or a hidden enemy within the village set him up.
Perhaps in the fanfiction, there's a misunderstanding within the werewolf pack. Some members believe Bella is a threat to their territory or secrets. They attack her without fully understanding the situation, and unfortunately, she is beaten to death. This could lead to a huge rift between the vampires and the werewolves, as Edward and his family would seek justice for Bella.
Perhaps in the fanfiction, Sakura fakes her death as part of a plan to deceive a rival ninja group. She might want to make them think they have won, and then when they let their guard down, she can strike back with a surprise attack. This could also involve her using a new, secret jutsu she has been developing.
A possible plot in a 'death of naruto fanfic' is that Naruto is killed in a political conspiracy within the ninja world. This could lead to a war between different ninja clans as they try to figure out who is responsible. Or perhaps Naruto's death is the result of a time - traveling enemy who changes the past in a way that Naruto no longer exists, and the story could be about his friends trying to reverse this change.
One possible plot could be a young soldier's journey towards death. He starts off full of hope and patriotism but gradually loses his will to live as he witnesses the horrors of war.
One possible plot could be that Natsu sacrifices himself to save his friends from a powerful dark magic. He might use all his power to defeat an ultimate evil, but in doing so, it drains his life force. Another plot could be a tragic accident during a mission where Natsu is caught in a powerful spell that he can't escape from and it ultimately takes his life. And perhaps there could be a situation where he is poisoned by a very rare and deadly substance that no one can cure in time.