One possible plot could be a character using the act of eating a pie as a form of comfort during a difficult time in the story.
One possible idea for this fan fiction could be that the snake is a magical creature in a fantasy world. It discovers a pie left by a human traveler. The snake, being curious, decides to eat the pie. As it takes a bite, it gains some strange powers related to the ingredients of the pie, like the ability to fly if the pie had feathers from a magical bird in it.
Sorry, I'm not aware of specific 'eating a pie' fan fiction. You could try searching on fan fiction websites like Archive of Our Own or FanFiction.net.
Well, it could be that the dragon is on a quest to find the most delicious pie in the land. After searching far and wide, it finally discovers a magical pie. The dragon then has to figure out how to eat it without using its fiery breath and ruining the taste. So it tries all sorts of comical ways, like using tiny utensils made for fairies.
A plot twist could be that the pie is poisoned. Just as the snake is about to finish the pie, it starts to feel ill. But then it turns out that the snake has a special immunity to the poison that was put in the pie by an evil character who wanted to harm anyone who ate it.
Perhaps there's a knight who is supposed to protect the pies from the dragon. But instead of fighting the dragon, he ends up making a deal with it. The knight will supply the dragon with a certain number of pies every week in exchange for the dragon not attacking the village.
Maybe Pinkie Pie is kidnapped by a group who wants to use her party - planning skills for their own evil purposes. Her friends, like Twilight Sparkle using her magic and Rainbow Dash her speed, try to track her down. They might also discover some secrets about Pinkie Pie's past during the rescue mission.
It could be that the pie is his favorite flavor or it's a special treat. Or perhaps it's part of a funny story or a challenge he's facing.
It could be that it's his favorite treat, or perhaps he's celebrating something and the pie is part of the celebration.
One possible plot could be Alexander's journey of struggling with his eating disorder, how he hides it from his friends and family at first. Then, as the story progresses, a close friend might start to suspect something and tries to help him face his problem.
There was a family having a picnic. They were enjoying some delicious pies. All of a sudden, a cold wind blew and a ghost appeared. The ghost seemed fascinated by the pie - eating scene. It started to mimic the family's actions of eating the pie, but every time it took a 'bite', the pie would disappear into thin air. The family was so scared that they left all their things and ran away.