I haver tracked down a song which could be the origin

One fine day in Hindustan,
I met a funny little man
With googly eyes and lantern jaws;
With a new silk hat and some old plus-fours
When I said to that quaint old chap;
Why do you carry that big steel trap
That butterfly net and that old gun?
He replied, Listen here my son.
"I'm looking for the Ogopogo.
The funny little Ogopogo.
His mother was an earwig,
His father was a snail
I'm going to put a little bit of salt on his tail
I want to find the Ogopogo,
While he's playing on his old banjo
The Lord Mayor of London,
The Lord Mayor of London
The Lord Mayor of London wants
To put him in the Lord Mayor's show."


http://books.google.co.uk/books?id=sol334hPuRoC&pg=PA418&lpg=PA418&dq=ogo+popo&source=bl&ots=FASJVEUvzS&sig=fKdjZILZHMXCuMhvQ-EIJtdjn3M&hl=en&sa=X&ei=H0a9UuufN5CBhAf84oCAAg&redir_esc=y#v=onepage&q=ogo%20popo&f=false