The seagull - appropriately named George - is believed to be one of two made by Wyllie to sit alongside his Funnel installation at the Glasgow Garden Festival.
It will go under the hammer at McTear's Scottish Contemporary Art Auction on Sunday.
When the Garden Festival ended, he gave it to a friend as a thank-you.
Yesterday George the gull met Scotstoun resident Susan Harris and feathered friends on a pre-auction outing to Victoria Park
Brian Clements of McTear's said: "This is a classic example of George Wyllie's work. Llike many of his pieces, brings a smile to your face every time you see it.
"George Wyllie has built up an international following and his works are found in prestigious galleries and private collections across the world.
"George the seagull is a wonderful piece - I have no doubt he will fly high when the bidding starts."
Mr Wyllie, who died in 2012, produced iconic works including the Straw Locomotive which hung from Glasgow's Finnieston Crane in 1987.