“A guy walks into a bar…” is a typical form of what has been called the “bar joke.” A goose version is:
 
“A goose walks into a bar. The bartender looks at him and says, ‘Hey, buddy, your pants are down!’”
 
The joke was posted on the newsgroup alt.humor.puns on September 28, 2001.
 
   
Google Groups: alt.humor.puns
Puns of the Weak 9/28/01
Stan Kegel
Sep 28, 2001, 11:29:01 PM
(...)
This goose walks into a bar and the bartender looks at him and says,
“Hey, buddy, your pants are down!” (Clean Laffs)
   
Twitter
Kelly Williams
@othlauren
A goose walks into a bar. The bartender looks at him and says, “Hey, buddy, your pants are down…” ... http://lnk.ms/1NpGS
3:52 PM · Oct 6, 2009·erased858
   
Twitter
Elizabeth Evans
@EClaireEvans
Replying to @_DarlingNy and @KillerMartinis
A goose walks into a bar.
Bartender yells “hey, buddy, your pants are down!”
3:21 PM · Jan 10, 2021·Twitter for iPhone
   
Twitter
Elizabeth Evans
@EClaireEvans
A goose walks into a bar.
Bartender yells, Hey, buddy, your pants are down!”Here endeth my entire knowledge of goose jokes.
Quote Tweet
slim
@_DarlingNy
· Jan 10
I’ve been laughing for 10 minutes.
3:22 PM · Jan 10, 2021·Twitter for iPhone
   
Twitter
smellsofbikes
@smellsofbikes
Replying to @_petitefromage_
It’s derived from my favorite joke: a goose walks into a bar.  Thr bartender says hey pal your pants are down.
If you don’t have the lead-in, it sometimes takes people quite a while to get it.
10:33 PM · Jun 2, 2021·Twitter for Android
 
Facebook
Indian Hills Community Sign
November 21, 2021 at 12:52 PM ·
A GOOSE WALKS
INTO A BAR
BARTENDER SAYS
HEY BUDDY, YOUR
PANTS ARE DOWN!