I like the witty and comfortable idea, and being me, think in the direction of some food concept.
Well, the first one that comes to mind is a collage I made in beginning design - I forget the assignment exactly, but let's say it was to express a concept in collage -
and I took Brillat-Savarin's "man is what he eats"....
present day link - http://www.phrases.org.uk/meanings/you%20are%20what%20you%20eat.html
"This phrase has come to us via quite a tortuous route. Anthelme Brillat-Savarin wrote, in Physiologie du Gout, ou Meditations de Gastronomie Transcendante, 1826:
"Dis-moi ce que tu manges, je te dirai ce que tu es." [Tell me what you eat and I will tell you what you are].
In an essay entitled Concerning Spiritualism and Materialism, 1863/4, Ludwig Andreas Feuerbach wrote:
"Der Mensch ist, was er ißt."
That translates into English as 'man is what he eats'.
Neither Brillat-Savarin or Feuerbach meant their quotations to be taken literally. They were stating that that the food one eats has a bearing on what one's state of mind and health.
The actual phrase didn't emerge in English until some time later. In the 1920s and 30s, the nutritionist Victor Lindlahr, who was a strong believer in the idea that food controls health, developed the Catabolic Diet. That view gained some adherents at the time and the earliest known printed example is from an advert for beef in a 1923 edition of the Bridgeport Telegraph, for 'United Meet [sic] Markets':
"Ninety per cent of the diseases known to man are caused by cheap foodstuffs. You are what you eat."
and used a big magazine ad for pork and beans, that was mostly beans, and maybe some pork and beans can wrap lettering and used some fancy font for the other lettering..
The teacher found it a little crude and gave me an a+. Hah, my first concept art, to explain, one was "full of beans".
Not that I recommend this for halloween, but playing with either food dicta or some famous quotes on whatever subject could be a possibility. Maybe song lyrics..