An interesting Adventure Time weight gain story could involve Lumpy Space Princess. She might visit a new dimension where everything is made of rich, creamy substances. She eats and eats, and her lumpy space body starts to expand. At first, she's horrified, but then she finds that her new, bigger lumps give her the ability to bounce higher and farther. This allows her to travel across different parts of Ooo much faster than before, and she starts to see her weight gain as a kind of superpower.
There could be a fanfic where Princess Bubblegum is conducting an experiment that goes wrong and results in her gaining weight. This could lead to a story about self - acceptance and how her kingdom still loves and respects her regardless. Maybe Marceline helps her through the process with her cool and carefree attitude.
One reason could be a change in her diet. If she starts eating more junk food like the sugary candies that are abundant in the Land of Ooo. For instance, if she befriends a candy - making gnome who gives her free samples all the time.
Once upon a time in Adventure Time, Finn and Jake were on a mission to help Princess Bubblegum. She had been working on a new experiment that involved a lot of delicious magical candies. Princess Bubblegum couldn't resist tasting them as she worked. As days passed, she started to gain weight. But instead of being sad, she found that her new rounder shape made her even more in touch with the magical essence of the candies. She then used this newfound connection to create a spell that saved the Candy Kingdom from a great danger.
One possibility is that in a time travel scenario, if a person travels to a time period with different food availability and lifestyle. For example, traveling to a time when food was scarce but suddenly finding an abundance of high - calorie foods that were not available in their original time. They might overeat due to the novelty and thus gain weight. Another factor could be related to time travel causing disruptions in the body's metabolism. If the time - traveling process somehow affects the body's internal clock which is linked to metabolism, it could lead to slower metabolism and subsequent weight gain.
In Adventure Time, perhaps Fionna stumbles upon a magical food source that is super delicious but also really fattening. Every time she eats it, she gains a little more weight. At first, she doesn't really notice, but as it adds up, she has to face the reality. Her friends might be a bit concerned at first, but then they support her in finding a balance between enjoying the new food and staying healthy. She could learn some valuable lessons about self - care and moderation through this experience.
There could be a fanfiction where Princess Bubblegum conducts an experiment that goes wrong and results in her own weight gain. In this story, she might have to figure out how to reverse the process while still ruling the Candy Kingdom. It could explore themes of self - acceptance and problem - solving.
One reason could be overeating. If she got into the habit of consuming large amounts of food without proper balance, it would lead to weight gain.
One reason could be a change in lifestyle. For example, if she used to be very active in the goth club scene, dancing all night, and then she has an injury or something that stops her from being so active, she may gain weight. Another reason could be a new hobby like baking goth - themed treats as I mentioned before. Also, a new relationship where her partner cooks a lot can lead to weight gain.
Poor diet. Maybe the teacher eats a lot of junk food like burgers and fries.
Another place could be FanFiction.net. It has a large collection of fanfics from various fandoms. Just be sure to use the search bar and be specific with your search terms like 'Adventure Time' and 'weight gain' to narrow down the results and find what you're looking for.