“What do you call an alligator in a vest?”/“An investigator.”

An alligator riddle that has been printed on images is:
 
Q: What do you call an alligator in a vest?
A: An investigator.
 
The alligator pun was posted on Twitter on September 20, 2010, but went viral on April 28, 2011.
 
       
Twitter
Antonio Hanna
@freefallstudios
Replying to @shakiratanah
@h0mesick Q: What do you call an Alligator in a Vest? A: An In-Vest-i-Gator!
10:21 PM - 20 Sep 2010
   
Twitter
Mica
@michelititaaa
Replying to @jennkloc
lol.. silly. RT @jennkloc What do you call an alligator in a vest? ... An investigator! HAHAHA!
12:55 AM - 28 Apr 2011
   
Twitter
Logan Beaty
@lbeaty1981
What do you call an alligator in a vest? An investigator!
10:51 AM - 28 Apr 2011
   
Twitter
Cortney Park
@cpark9
I actually laughed at this…Am I 5? RT @crashtestdummyX: What do you call an alligator in a vest?
An investigator! #bestjokeever
11:49 AM - 28 Apr 2011
   
2 October 2011, The People (London, UK), pg. 14:
What do you call an alligator wearing a vest?
An investigator.
       
Google Books
Funny Animal Jokes For Kids
By Peter Crumpton
PeteyRF Creative
2015
Pg. ?:
What do you call an alligator in a vest?
An investigator.
   
Google Books
Happy Smile:
Jokes for Kids
By Adam Smith
Lulu Press (Lulu.com)
2017
Pg. ?:
Q: What do you call an alligator in a vest?
A: An Investigator.
 
Reader’s Digest
August 1, 2017
25 Corny Jokes Everyone Will Laugh at to Celebrate National Tell a Joke Day
BY JULIA K. PORTER
(...)
What do you call an alligator detective? An investi-gator.
(Did you know avocados are known as “alligator pears”?)
 
Twitter
EmilyDirectioner1D
@FicoEmilia
What do you call an alligator in a vest?
An investigator!
#OneDirectionBestFans
9:14 AM - 7 Mar 2018