This may fall into the 'too much time on our hands' category, but the folks at How It Should Have Ended have taken the time to re-edit scenes from the classic 1964 Mary Poppins to replace star Julie Andrews with Michael Rooker done up as Yondu Udonta from Guardians of the Galaxy.
This all comes about because of the line fan-favorite line from Guardians of the Galaxy Vol. 2 when Yondu is using his arrow to slow his descent to the ground and Peter Quill (Chris Pratt) looks up and comments how he looks like Mary Poppins. Yondu, of course, asks, "Is he cool?" and Quill, instead of taking a shot, just said yeah… leading to the line, "I'm Mary Poppins, y'all!"
Since the film came out, there has been a lot of fan art combining Yondu and Poppins, as well as cosplayers making mash-up costumes. Mary Poppins has return to popularity lately with a sequel in production with Emily Blunt and Lin-Manuel Miranda starring in the Andrews and Dick Van Dyke roles. Mary Poppins Returns is slated for a December 25th, 2018 release.
The two-and-a-half-minute video below does a pretty nice job of merging footage from the Marvel film into the old Disney classic.