“How could the dolphin afford to buy a house?”/“He prawned everything.”

“Prawn” sounds to some like “pawn.” A riddle is:
 
Q: How could the dolphin afford to buy a house?
A: He prawned everything.
 
The joke was posted on the newsgroup uk.people.silversurfers on March 21, 2002.
   
“Where do shellfish go to borrow money?”/“The prawn broker” is another “prawn”/“pawn” joke.
 
       
Google Groups: uk.people.silversurfers
Fish jokes
Anita Carter
3/21/02
(...)
How could the dolphin afford to buy a house ?
He prawned everything !
       
9 March 2003, Sunday Telegraph (Surry Hills, New South Wales), “The Funday Telegraph,” pg. F1:
Q: Why could the dolphin afford to buy a house?
A: Because he prawned everything!
 
Google Books
Shark Tale:
Joke Book
By Jesse Leon McAnn
London, UK: Scholastic
2004
Pg. ?:
How could the dolphin afford to buy a house?
He prawned everything!
 
Twitter
HapaSushi‏
@HapaSushi
How could the shrimp afford to buy a house?
He prawned everything!
3:32 PM - 2 Apr 2009
 
Twitter
Fish Chat‏
@Fish_chat
How could the dolphin afford to buy a house?...He prawned everything
11:17 AM - 11 May 2009
     
Google Books
Marcy: Thirteen Dolphins
By Susan Halliday
Melbourne, Australia: Ford Street Publishing
2013
Pg. ?:
A joke from Bella:
Q: How did the dolphin afford to buy a house?
A: He prawned everything!
   
Google Books
Sensible Nonsense.. Frank’s Comic Pack:
Humour Pack Series
By Frank Paul
BookBaby
2014
Pg. ?: 
How could the dolphin afford to buy a house ?He prawned everything !
 
Twitter
Lucky Score‏
@LuckyScoreNet
How could the dolphin afford to buy a
house ?
He prawned everything !
#Joke from #VariousAnimalJokes in #Jokes, #Humor and #Satire
7:10 PM - 14 Jan 2018