Comic-Con
2012:
The Unexpected Marvel/Disney Crossover!
Phineas and Ferb know what they're going to do today: blow your mind with the fact that they will meet the Avengers next summer!
According to today's announcement, in "Phineas and Ferb: Mission Marvel," Spider-Man, Iron Man, Thor and Hulk enter Danville after Dr. Doofenshmirtz's latest "inator" scheme accidentally removes their powers and immobilizes them. Now it's up to Phineas and Ferb to team up with the Marvel Super Heroes to help them regain their powers and defeat Marvel Super Villains – Red Skull, Whiplash, Venom and M.O.D.O.K. – who are working together with Dr. Doofenshmirtz to use his power-draining technology to create mayhem.
This has to beat the previously hinted Big Hero 6 animated feature, and despite Marvel heroes having shows on Disney XD, this may be the first official crossover project to make it to fans!