“A guy walks into a bar...” is a typical form of what has been called the “bar joke.” A corn stalk version is:

“A corn stalk walks into a bar. The bartender says, ‘Wanna hear a good joke?’ The corn stalk says, ‘I’m all ears!’”

The joke has been cited in print since at least 2008.


Subversive Intelligence
Random Acts of Linkage #77
by Brother Maynard | Sep 13, 2008
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A corn stalk walks into a bar. The bartender says, “Wanna hear a good joke?” The corn stalk says, “I’m all ears!”

Twitter
Todd Halfpenny
‏@toddhalfpenny
- A corn stalk walks into a bar. The bartender says, “Wanna hear a good joke?” The corn stalk says, “I’m all ears!”
5:30 AM - 16 Nov 2008

CCDV Message Board
Walks into a bar - Part III
carboman
12-12-08, 10:47 PM
A corn stalk walks into a bar. The bartender says, “Wanna hear a good joke?” The corn stalk says, “I’m all ears!”

Google Books
The Best ‘A Man Walks Into A Bar’ Jokes
By Billy Brownless
Crows Nest NSW: Allen & Unwin
2009
Pg. 34:
A cornstalk walks into a bar. The bartender says, ‘Wanna hear a good joke?’ The cornstalk says, ‘I’m all ears!’

Walks Into a Bar Jokes
TUESDAY, MARCH 17, 2009
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A corn stalk walks into a bar. The bartender says, “Wanna hear a good joke?” The corn stalk says, “I’m all ears!”

wb4all
July 13, 2009
Cool Dumb Jokes: “Walks Into A Bar”
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A cornstalk walks into a bar.  The bartender says, “Want to hear a good joke?” The cornstalk says, “I’m all ears”

Google Groups: rec.boats
So…
Loogypicker
1/5/10
(...)
A corn stalk walks into a bar, the bartender says “Want to hear a good joke?”

The corn stalk says - “I"m all ears.”

Bicycling
So a mushroom walks into a bar
QUESTRIDER
3/10/11 5:21 PM
A cornstalk walks into a bar and the bartender says “want to hear a good joke?” The cornstalk replies “I’m all ears”.

Facebook
JOKES.com
July 14, 2011 ·
A corn stalk walks into a bar. The bartender says, “Wanna hear a good joke?” The corn stalk says, “I’m all ears!”