For a crossover with 'Avatar: The Last Airbender', Aang, Katara, Sokka and Toph would be great inclusions. Aang's airbending and his fun - loving nature could pair well with Phineas and Ferb. Katara could use her waterbending to help with any water - related problems in the crossover. Sokka could contribute his strategic thinking, and Toph with her earthbending could be involved in building or demolishing things as part of the adventure. Zuko could also be added later for some extra drama and character development.
In a crossover with 'Gravity Falls', Dipper and Mabel would be great characters to include. Dipper's curiosity and Mabel's wackiness could blend well with Phineas and Ferb's adventures. They could all team up to solve a mystery that involves both the strange happenings in Gravity Falls and Phineas and Ferb's crazy inventions. Another good character could be Perry the Platypus. Since he is a secret agent, he could have some interesting interactions with other characters from different shows in a crossover.
If it's a crossover with 'Adventure Time', Finn and Jake would be awesome. Finn's heroism and Jake's shape - shifting abilities could add a lot to the story. They could join Phineas and Ferb in building something amazing or go on a quest together. Also, Marceline the Vampire Queen could be an interesting addition. Her cool and sometimes dark personality would contrast with the more light - hearted nature of Phineas and Ferb's world. And don't forget about Princess Bubblegum, who could collaborate with the boys on some scientific projects.
Candace could be a main character. Since Ferb is sick, she might be in a bit of a dilemma. On one hand, she still has her urge to bust Phineas if he does something out of the ordinary while taking care of Ferb. But on the other hand, she also cares about her brother and might be more lenient or even helpful.
One idea could be a crossover with 'Kim Possible'. Phineas and Ferb could use their inventive skills to help Kim in one of her missions against Dr. Drakken. Maybe they create some high - tech gadgets for her. Another idea is a crossover with 'The Simpsons'. The boys could visit Springfield and get involved in some wacky adventures with Homer and Bart. They might even build an amazing contraption in the Simpsons' backyard.
Well, Naruto could visit the world of Phineas and Ferb. He might be really confused by all the crazy inventions that Phineas and Ferb create every day. And he could show them some of his ninja skills, like running up trees or making clones. Maybe Ferb would be interested in learning some ninja techniques to add to his own knowledge of building things.
I really like 'Phineas and Ferb Crossover with Star Wars'. It's a really cool fanfic. In it, Phineas and Ferb end up in the Star Wars universe. They use their skills to help the rebels. Ferb is like a super mechanic for the X - wings and Phineas comes up with plans to outwit the Empire. It's full of action and adventure.
In this crossover fanfiction, the Marvel heroes could visit the world of 'Phineas and Ferb'. Spider - Man would be swinging around Danville, impressing the local kids. The Phineas and Ferb gang could show the Marvel heroes how they build those huge and elaborate projects in just one day. And there could be a plot where Doctor Doom tries to steal the boys' inventions to take over the world, and the combined forces of 'Phineas and Ferb' and the Marvel heroes have to stop him.
To write a great 'Phineas and Ferb Crossover Fanfic', start by choosing a crossover that has potential. If it's a crossover with a superhero universe like DC, think about how Phineas and Ferb's normal day - to - day building would be affected by superpowers. Also, don't be afraid to add some humor. Since Phineas and Ferb is a comical show, humor can make the crossover even better. You can also include some challenges for the characters to overcome, like Phineas having to build something without his usual tools in the new crossover universe.
Well, Mom would be very concerned. She would drop whatever she was doing and take care of Phineas. She might make some of her special home remedies to help with the diarrhea. Dad, on the other hand, would try to be the joker and make Phineas laugh to take his mind off the discomfort. And Doofenshmirtz, if he somehow gets wind of this, might try to use it as an opportunity to create a new -inator to stop the boys' fun, but in the end, it could backfire on him as he realizes it's not a good thing to take advantage of a sick kid.
One possible plot could be that Phineas and Ferb build a super - advanced lightsaber - like device in their backyard. Meanwhile, the Star Wars characters mistake it for a new Sith weapon. Then, Phineas and Ferb get caught up in the Star Wars universe and have to use their creative skills to help the Jedi defeat the Sith.
I think Phineas and Iron Man would be an interesting pair. Phineas is full of wild ideas and Iron Man is a genius inventor. They could bounce ideas off each other and come up with some really out - of - this - world inventions together.
I think Naruto would be the most interesting. He has such a unique background and abilities. His ninja skills and his journey to become Hokage would contrast so much with the laid - back, creative world of Phineas and Ferb. He could bring a whole new level of action and adventure to their world.