“My shoe has caught a Pig
I am a Pig Trap”

Manuel, in Ch. I : How Manuel Left the Mire
Figures of Earth (1921)
Context: I shall not ever return to you, my pigs, because, at worst, to die valorously is better than to sleep out one's youth in the sun. A man has but one life. It is his all. Therefore I now depart from you, my pigs, to win me a fine wife and much wealth and leisure wherein to discharge my geas. And when my geas is lifted I shall not come back to you, my pigs, but I shall travel everywhither, and into the last limits of earth, so that I may see the ends of this world and may judge them while my life endures. For after that, they say, I judge not, but am judged: and a man whose life has gone out of him, my pigs, is not even good bacon.

AronRa vs Ray Comfort (September 17th, 2012), Radio Paul's Radio Rants

Christopher Soames, speech at the Reform Club (28 April 1981), reported in Martin S. Gilbert, Winston S. Churchill. Volume Eight: Never Despair: 1945–1965. p. 304
Post-war years (1945–1955)
Variant: I like pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.
Context: [Christopher Soames, Churchill's future son-in-law, remembered] Churchill showing him around Chartwell Farm [around 1946]. When they came to the piggery Churchill scratched one of the pigs and said: I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.

Source: The Chronicles of Prydain (1964–1968), Book II: The Black Cauldron (1965), Chapter 1 (Ellidyr)

Source: The Chronicles of Prydain (1964–1968), Book V : The High King (1968), Chapter 21
Context: “Long ago I yearned to be a hero without knowing, in truth, what a hero was. Now, perhaps, I understand it a little better. A grower of turnips or a shaper of clay, a Commot farmer or a king — every man is a hero if he strives more for others than for himself alone. Once,” he added, “you told me that the seeking counts more than the finding. So, too, must the striving count more than the gain.
“Once, I hoped for a glorious destiny,” Taran went on, smiling at his own memory. “That dream has vanished with my childhood; and though a pleasant dream it was fit only for a child. I am well content as an Assistant Pig-Keeper.”

Section 38 (p. 118)
Venus Plus X (1960)

Source: The Black Cauldron

Criticizing Hillary Clinton's health-care plan as being "eerily reminiscent" of the plan she advocated as First Lady, 11 October 2007 http://www.latimes.com/news/nationworld/washingtondc/la-na-campaign10-2008sep10,0,311675.story
2000s, 2007

" A welcome in the hillside http://www.camdennewjournal.com/welcome-hillside", interview with John Gulliver, in Camden New Journal (13 August 2015).
2000s