While it's not exactly a major role in the Marvel Cinematic Universe, it certainly would have made at least one Marvel hero's solo outings a lot different had Mel Gibson decided to play the part. 

According to the Lethal Weapon star, he turned down the role of Odin in Thor. The role was of course played by Anthony Hopkins who added the much needed gravitas to the Kenneth Brannagh directed original. 

While promoting his new movie, Blood Father, Gibson weighted in on Marvel and the rise of the superhero movie: 

“Some are good. Some are kind of funny … Guardians of the Galaxy. Or the first Iron Man. And some of them are just like retreats. I mean you can watch them do Spider-Man five times … There is a slight shift in film. But, then again, I think all films are suffering from people not being able to now open them with their name. It’s a different kind of business these days.”

While the role of Odin probably wouldn't have revitalised Gibson's flailing career in the same manner Iron Man did for Robert Downey Jr. it might have given him the platform to get his career back on track. 

We're glad he didn't though because Hopkins was without question the best choice for Odin. 

Via Uproxx