"I think baseball is such a team game that it's an easy way for guys to express their personalities, " said Sal Fasano, a former backup catcher whose burly 'stache was inspired by old samurai movies that he watched as kid.

WSJ: The Baseball Mustache: A Tradition With All the Trimmings

It's no surprise all this could lead to Michael Cera and Jason Schwartzman clashing swords in the comic-book-and-videogame-inspired movie "Scott Pilgrim vs. the World" (2010), or Emily Browning facing a giant samurai in "Sucker Punch" (2011).

WSJ: Hollywood's New Kick: Why Everybody Is Kung Fu Fighting