Possibly one of those butterfly wing things. Somebody said it at a party, and a scriptwriter heard it. The scriptwriter wrote it into the show and a lot of other people heard it and repeat it. It's a fad phrase.

The phrase 'hunker down' was all over the place during Gulf War I. People do this with songs, too. Have you ever gone to a festival and heard one song sung several times, by different performers? You go home, and the next time your around a group of people who are singing, somebody sings it. (And the guy sitting next to him exclaims, "Damn! I wuz gonna sing that!) It's oral transmission, alive and well in the 21st century. Can't help it - human beings are hard-wired to hear and (creatively) repeat.

Have some fun - start saying it wrong and see how far the wrong version will get. Maybe "One track pony," or instead of "He's a one-trick pony," say, "He's won a trick pony."