“Why did the clown cross the road?”/“To find his rubber chicken.”

“Why did the chicken cross the road?”/“To get to the other side” is a classic riddle from the 19th century. A clown version is:
   
Q: Why did the clown cross the road?
A: To find his rubber chicken.

       
“Why did the clown cross the road? To rob a Kwik-E-Mart” was posted on the newsgroup alt.tv.simpsons on April 6, 1992. The rubber chicken punchline has been cited in print since at least 2000.
         
“Why did the rubber chicken cross the road?”/“She wanted to stretch her legs” and “Why did the rubber chicken cross the road?”/“To get to the rubber side” are other “rubber chicken” riddles.
     
 
Wikipedia: Rubber chicken
A rubber chicken is a prop used in comedy. The phrase is also used as a description for food served at speeches, conventions, and other large meetings, and as a metaphor for speechmaking.   
   
Google Groups: alt.tv.simpsons
[7G12] Krusty Get Busted (!)
Raymond Chen
4/6/92
(...)
Why did the clown cross the road?
To rob a Kwik-E-Mart.
A new story behind that enigmatic half-joke after this commercial message.
—Scott Christian anchors the newscast, ``Krusty Gets Busted’‘
 
30 October 2000, Ukiah (CA) Daily Journal, “Kid Scoop,” pg. 12, col. 2:
Why did the clown cross the road?
ANSWER: To find his rubber chicken.
   
7 November 2000, The Tribune (Seymour, IN), “Kid Scoop,” pg. 4B, col. 2:
Why did the clown cross the road?
ANSWER: To find his rubber chicken.
 
Twitter
Phyllis King‏
@PhyllisKing
Q: Why did the clown cross the road? A: To find his rubber chicken.
10:36 AM - 17 Dec 2009
 
Twitter
Andrew L. Acosta‏
@Andrew_Acosta
Q: Why did the clown cross the road? A: To find his rubber chicken.
11:46 PM - 20 Dec 2009
   
Google Books
Sensible Nonsense.. Frank’s Comic Pack:
Humour Pack Series

By Frank Paul
BookBaby
2014
Pg.?:
Q: Why did the clown cross the road? A: To find his rubber chicken.
   
Twitter
Lucky Score‏
@LuckyScoreNet
Q: Why did the clown cross the road? A: To
find his rubber chicken.
#Joke from #Humorjokes in #Jokes,  #Humor and #Satire
11:27 AM - 7 Sep 2017