A cow riddle is:
   
Q: What do you call a cow in a tornado?
A: A milk shake.
 
The joke has been cited in print since at least 2007.
     
“What do you call a cow during an earthquake?”/“A milk shake” and “What do you call a cow on a trampoline?”/“A milk shake” are similar riddles.
       
   
12 March 2007, Coventry UK) Telegraph, “Time for a Laugh,” pg. 16.
What do you call a cow in a tornado?
A milkshake.
Liam Kelly, year 5.
   
Twitter   
Lucky realles
@Real_L3S
Q:what do you call a cow in a tornado? A:milk-shake
3:08 PM · Dec 12, 2011·Mobile Web
         
Twitter
Jerry Evans Jr
@JEJ_2
what you call a cow in a tornado ?????? a milk shake lmao!!!!!!
1:15 AM · Aug 16, 2012·Twitter Web Client
 
Google Books
Silly Animal Jokes and Tongue Twisters! Includes Cats, Dogs, Frogs, Toads, and Barnyard Animals
By Mrs. Barberelli
Morrisville, NC: Lulu Press, Inc.
2018
Pg. 81:
Q: What do you call a cow in a tornado?
A: A milkshake!
 
Google Books
Dog Humor
By Oliver Gaspirtz
Westhoff Publishing
2020
Pg. 104:
Q: What do you call a cow in a tornado?
A: A milkshake.
 
Twitter
Bad Jokes Bear
@BadBritishJokes
What do you call a cow in a tornado?
A milkshake.  #joke #dadjokes
3:00 PM · Aug 4, 2020·Bad British Jokes tweeter