“Taco cat spelled backwards is taco cat” is a popular sentence with a palindrome (“taco cat”). “Taco cat” has many internet images of a cat inside a taco.
 
The “taco cat” palindrome has been cited in print since at least 1992.
   
             
9 July 1995, New York (NY) Times, “On Language: Surveilling Maskirovka” by Willliam Safire, pg. A12:
Every year, somebody comes out with a collection of them (palindromes—ed.) that hooks me. This year’s is by Craig Hansen, from Plume Books, titled “Ana, Nab a Banana,” where the taco cat pursues sleek eels.
 
Google Books 
I Love Me, Vol. I:
S. Wordrow’s Palindrome Encyclopedia : Being a Magic Mirror, Master Key, and Treasure Map to Some Well-defined Cracks and Hot Spots in Reality (all-round Trips) Arranged Alphabetically from AA to ZZZ-ZZZ-ZZZ
By Michael Donner
Chapel Hill, NC : Algonquin Books
1996
Pg. 358:
Taco Cat. Illustrated in irvine, 1992.
 
Google Groups: alt.games.creatures
[Story] HoloDeck 32
Bean 118
5/21/99
(...)
>> Yey is a pallendrome.
>
>So’s *live evil*!
And Taco Cat.. wait, Live Evil?
 
Twitter
Derek
‏@perezd
TACO CAT IS PALINDROME
3:02 PM - 14 Nov 2007
     
Urban Dictionary
Tacocat
Tacocat is the greatest palindrome to ever exist…. ever
holy shit… did you know that tacocat spelled backwards is tacocat?!?!?!
#tacocat#palindrome#taco#cat#awesome
by Alex Saffle October 19, 2008
   
Twitter
Cynthia ☠️
@cynthiaa_rockss
Replying to @kidquizine
@kidquizine lol taco cat spelled backwards is taco cat lol niceee one 😊
4:52 PM - 27 Sep 2009
 
Twitter
INTERNET WIZZARD
‏@count_01
@tweetzydeetzy Taco cat is a palindrome http://icanhascheezburger.com/2007/11/12/tacocat-is-a-palindrome/
7:00 PM - 17 Nov 2009
 
Google Books
C# 5.0 Programmer’s Reference
By Rod Stephens
John Wiley & Sons, Inc.
Indianapolis, IN
2014
Pg. 340:
A palindrome is a string that is the same forward as backward, ignoring capitalization and punctuation: “Taco cat” and “nurses run.”
 
Twitter
Taco Cat
‏@crazyn0w_
YOU GUYS I’M DYING BECAUSE TACO CAT SPELLED BACKWARDS IS TACO CAT
9:29 PM - 7 Dec 2014
 
Reddit—Aww
Taco Cat spelled backwards (i.imgur.com)
submitted December 17, 2014 by mike_pants
     
Reddit—Thisismylifemeow
TacoCat Backwards is TacoCat (i.redd.it)
submitted October 30, 2017 by timmayayay
 
(Trademark)
Word Mark TACO CAT
Goods and Services (ABANDONED) IC 043. US 100 101. G & S: Providing of food and drink via a mobile truck
Standard Characters Claimed
Mark Drawing Code (4) STANDARD CHARACTER MARK
Serial Number 85703459
Filing Date August 14, 2012
Current Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) Laeger-Hagemeister, Daniel INDIVIDUAL UNITED STATES 3629 Colfax Minneapolis MINNESOTA 55409
(APPLICANT) Jimerson, Tristan INDIVIDUAL UNITED STATES 3629 Colfax Minneapolis MINNESOTA 55409
Type of Mark SERVICE MARK
Register PRINCIPAL
Live/Dead Indicator DEAD
Abandonment Date June 18, 2013