Wolfcastle is an Austrian, muscular actor that sometimes appears on The Simpsons show to represent the action movie star trope. And if "Austrian", "muscular actor" and "action movie star" made you think of Arnold Schwarzenegger, then you have the right idea about who inspired Wolfcastle's character. The show creators couldn't make it more obvious that Rainier Wolfcastle is a parody of Arnold Schwarzenegger, right?