This joke about the black English dialect (African American Vernacular English) appeared by at least 1986:

Heard about the new toy store in Harlem?
It’s called “We Be Toys.”

There is no Toys “R” Us store in Harlem.


Wikipedia: Toys “R” Us
Toys “R” Us is a toy store chain headquartered in Wayne, New Jersey, United States. The chain also has locations in Europe, Asia, Oceania, Africa, Finland, Canada and Australia. The company currently operates 840 stores in the United States and 716 stores in 34 other countries, with some of them under franchises or licenses. The flagship store in New York City’s Times Square is the largest toy store in the world, featuring a colorful Ferris wheel. It is the largest toy-centered retailer and the second largest overall toy retailer in the United States. “R” is an abbreviation for the word “are”.

28 April 1986, Atlanta (GA) Journal and Constitution, “English, the language of success” by Chet Fuller, pg. A8: 
If black folk ran the highly successful chain of toy stores known as “Toys R Us,” according to a popular joke, they would call it “We Be Toys.” Funny joke. At first. Then comes the stinging aftertaste.

Google Books
Jokes My Mother Never Told Me
By Mark Barry
New York : Shapolsky Publishers
1990
Pg. 169:
How about a toy store in Harlem?
“We-Be-Toys"!

Google Books
Blanche Knott’s Treasury of Tastelessness
By Blanche Knott
New York, NY: St. Martin’s Press
1994
Pg. 33:
Heard about the new toy store in Harlem?
It’s called “We Be Toys.”

Google Books
Spoken Soul:
The story of black English
By John Russell Rickford and Russell John Rickford
New York, NY: John Wiley & Sons, Inc.
2000
Pg. 256:
Bill Cosby’s “We Be Toys” joke was recounted in the Wall Street Journal, January 10, 1997.

Google Books
The Language of Argument
By Larry W. Burton and Daniel Lamont McDonald
New York, NY: Pearson Longman
2005
Pg. 56:
I remember one day 15 years ago, a friend of mine told me a racist joke.

Question: Do you know what Toys “R” Us is called in Harlem?
Answer: We Be Toys.