“McBain” was originally the name of an action movie character on The Simpsons , played by an analogue of Arnold Schwarzenegger. His appearance on The Simpsons predates the release of the film McBain , and apart from the name, the film has very little relation to the character.[1]
Nonetheless, the producers of the movie refused to give 20th Century Fox and Matt Groening’s production team clearance to use the name “McBain”. In order to continue using the character, the character resorted to using the name of the actor portraying McBain, Rainier Wolfcastle (the name “McBain” does continue to be used throughout the Simpsons universe, to refer to the character played by Wolfcastle).[2]
Weird. So even though the character from the Simpsons predates the Walken character, the live action movie producers somehow had rights to it already?
I guess maybe the Simpsons folks originally had plans to use “McBain” as the name of both the character and the " actor" who plays him, so they invented the Rainer Wolfcastle name (the last name being an obvious homage to Castle Wolfenstein), and that was enough to satisfy the other folks.