“What always comes at the end of Thanksgiving?”/“The letter G.”

A popular Thanksgiving riddle is:
 
Q: What always comes at the end of Thanksgiving?
A: The letter “g.”
 
The riddle has been cited in print since at least 2006, when it was included on a web page of Thanksgiving jokes and riddles.
 
       
Brownielocks—Thanksgiving Jokes and Riddles (November 17, 2006)
62. What always comes at the end of Thanksgiving?
The letter G
   
19 November 2006, Pantagraph (Bloomington, IL), “Riddle Me This,” Flying Horse, pg. ?, col. 5:
Q: What always comes at the end of Thanksgiving?
A: The letter “g.”
   
Matchdoctor
Short Thanksgiving Jokes
posted 11/25/2008 8:13:58 AM
(...)
What always comes at the end of Thanksgiving?
The letter “g”!
 
Twitter
OCAEC
‏@OCAEC
Thanksgiving literature (?): What always comes at the end of Thanksgiving?  The letter “G!”
9:34 AM - 12 Nov 2009
   
Google Groups: FISICA_TEORICA
Thanksgiving Guide For Teachers: Teacher Tips #539
Teacher Tip Newsletter
11/7/10
(...)
Jokes You Can Tell in Class
What always comes at the end of Thanksgiving?
The letter G!
 
Facebook
Wishing you a safe & warm Thanksgiving!
November 24, 2010 at 12:00pm
(...)
What always comes at the end of Thanksgiving?
The letter G
 
Google Books
The Happy Classroom:
From Ha-Ha to A-Ha
By janet Aaker Smith
Marion, IL: Pieces of Learning
2011
Pg. 87:
What always comes at the end of Thanksgiving?
“G.”
   
Google Books
Thanksgiving Jokes For Kids
By Peter Crumpton
PeteyRF Creative
2015
Pg. ?:
What always comes at the end of Thanksgiving?
The letter G!