The young Eevee could lose its chew toy and be really sad. Then it starts looking everywhere for it. It might search in the tall grass where other small Pokemon live and ask them if they've seen it.
One idea could be that the young Eevee is on an adventure to find the perfect chew toy. Maybe it's a special toy that has some sort of hidden power. Along the way, Eevee meets different Pokemon who either help or hinder its search.
Well, Eevee could be in a contest. As it shows off its moves, it wags its tail. The judges are charmed by this cute display, and it helps Eevee win the contest. This would be a simple yet engaging fanfiction plot.
Ash's Eevee could learn some unique moves that are not common for Eevee. For example, it might learn a psychic - type move on its own, which could be a sign of its special potential. This could help Ash in battles against tough opponents like Team Rocket's more powerful Pokemon.
A new type of Pokémon treat could make Eevee wag its tail with excitement. Eevee has a big appetite for delicious things, and a special treat that it has never tasted before would surely get it excited.
Well, perhaps Pikachu would go on a heroic quest to rescue Ash. It might team up with other Pokémon like Charizard. They could follow the kidnappers' trail, facing various challenges along the way, like battling wild Pokémon or getting through difficult terrains.
Maybe in the fanfiction, Eevee and Vulpix are both lost in a mysterious forest. They start to look for a way out together. Along the way, they come across ancient Pokémon ruins. Inside the ruins, there are puzzles and traps. Eevee, being a very adaptable Pokémon, uses its different forms' abilities (even if it doesn't actually change forms yet in the story) to solve some of the puzzles. Vulpix uses its fire to light the way and keep away any dangerous Pokémon that might lurk in the dark corners of the ruins. As they progress, they become closer friends and finally find their way out of the forest.
Well, it could happen if there was some sort of magical cross - over event. Maybe a powerful wizard accidentally casts a spell that transports Harry into the world of Pokémon, specifically the world of Eevee. And there, he gets fascinated by the cute and diverse forms of Eevee.
Well, in this fanfiction, perhaps Eevee is in a situation where it has to use its puppy dog eyes to its advantage. It could be facing a tough Pokémon battle and uses those endearing eyes to either intimidate the opponent or gain some sort of strategic edge. Maybe it's trying to convince a human character to let it explore a new area that's usually off - limits. Without reading the actual fanfiction, it's hard to say for sure, but these are some possible ideas.
They could have an adventure exploring the new areas of the pizzeria that are usually off - limits. Maybe they find a hidden room filled with old animatronic parts.
One idea could be an Eevee that is born with a rare genetic mutation that gives it a new, unheard - of evolution type. The story could follow its journey as it tries to figure out this new power while facing both friends and foes who either want to help or take advantage of it.