One plot idea could be Waddlesworth getting lost in the big city and having to find his way back to the Dalmatians. He could encounter various other animals along the way, some friendly and some not so much, which would make for an exciting adventure.
A more character - driven plot could be about Waddlesworth trying to fit in better with the Dalmatians. He feels a bit like an outsider at times because he's not a Dalmatian. So, he goes on a journey of self - discovery and friendship - building within the Dalmatian family. He could learn valuable lessons about acceptance and the importance of being true to himself.
In a fanfiction, Waddlesworth and Oddball could be the heroes of the Dalmatians. When the group of Dalmatians is in trouble, perhaps facing a new villain who wants to capture them all. Waddlesworth, with his cleverness, and Oddball, with her unique skills (maybe she can do something extraordinary because of her different genes), they team up to outwit the villain and save their Dalmatian family.
A plotline could be that Waddlesworth and Oddball get separated from the rest of the Dalmatians during a journey. They then have to rely on each other to survive in the wild. They face various challenges like finding food and shelter, and along the way, they grow closer as friends.
A more complex idea for 101 dalmatians fanfiction could involve a mystery. For example, strange things start happening around the dalmatians' home. Items go missing, and there are strange noises at night. One of the more curious dalmatians decides to solve the mystery, suspecting that it might be a jealous neighbor or an escaped circus animal.
One idea could be exploring the adventures of the 103 dalmatians in a new city. They could encounter different dog breeds and have to work together to overcome challenges like finding a safe place to stay or getting enough food.
One idea could be a story where one of the dalmatian puppies gets lost during a family outing and has to find its way back home by following the scents and memories of the places they've been. It could face various challenges like crossing a busy road or avoiding other unfriendly animals.
A plot could revolve around Roger and Anita hosting a big party for all the dalmatians' friends. They have to plan everything from the food to the entertainment. Roger might be in charge of the music and Anita the decorations. Along the way, they encounter some problems like not having enough food or a sudden rainstorm threatening to ruin the party, but they manage to solve them together.
One idea could be exploring how the dalmatians' world is connected to the Kingdom Hearts universe in terms of magic. Maybe the dalmatians have a special kind of magic within them that can help Sora in his battles. Another could be a story where the dalmatians are being hunted by Heartless and Sora has to protect them. Also, perhaps there's a secret about the dalmatians' spots that has significance in the Kingdom Hearts lore.
One idea could be that the puppies discover a hidden map in their doghouse that leads them to a long - lost treasure of the Dalmatians. They then have to outwit Cruella de Vil's descendants who are also after the treasure. Another could be that the puppies befriend a group of stray animals in the city and together they work to rescue a group of kidnapped puppies from an illegal pet - trading ring. A third idea is that the puppies find a magical portal that transports them to a different world where they have to use their wits and unique Dalmatian skills to find their way back home while also helping the creatures in that strange world.
You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own. They have a wide variety of fanfictions. Just search for '102 Dalmatians Waddlesworth' in their search bars, and you might find some great stories.
One idea could be Penny's adventures in the city before she meets the Dalmatians. Maybe she's on a quest to find a special item and her path crosses with the puppies by chance.