Fans have long clamoured for a crossover of characters from Marvel Studios films (ie. one or more of The Avengers) with other Marvel-verse heroes currently owned by rival studios - namely Sony's "Spider-Man" and Fox's "X-Men" franchises.
Surprisingly, that almost happened a little over a decade ago and we've only now found out about it. In an interview with The Huffington Post, actor Hugh Jackman said he almost had a cameo in Sam Raimi's first Tobey Maguire-led "Spider-Man" in 2002.
Unfortunately an unexpected issue prevented it, and not a legal one as you might think:
"In the first "Spider-Man" -- Kevin Feige reminded me of this -- we really tried to get me to come on and do something, whether it was a gag or just to walk through the shot or something.
The problem was, we couldn't find the suit. The suit was stuck in some thing. And so when they were in New York when I was there, we couldn't get it together.
So, you know, I actually asked some high level people about it. Because the optimist in me goes, 'Why not? Why can't we do it? You know, a split cast or whatever?' And someone reminded that the amount of money Fox paid compared to the amount of money Disney paid is very different [laughs].
So how you split that pie up? God knows. But in the comic books, what's great about it is they're just mashing together all the time -- and it's awesome. And people are like, 'Yeah, well, let's get this one with that!' And, you know, I still think, one day, there may be an ability to do it."
Source: The Huffington Post