The World Aquarium in St Louis has been home to We, a one-of-a-kind two-headed albino rat snake, since 1999.
Aquarium president Leonard Sonnenschein has decided to sell the reptile, and bidding on e-Bay will start at $150 000 (R950 000).
Sonnenschein said: "When people see it they are awe-struck."
The 6-year-old snake came to the aquarium's attention when its previous owner distributed a circular offering it for sale days after its birth.
The aquarium paid $15 000 (about R95 000), knowing full well that most two-headed snakes don't live more than a few months.
But We has survived and thrived. At 2.5cm thick and 1.2m long, she is a healthy size for a rat snake.
While her body is white, the heads have a reddish appearance.
We has survived because, unlike some two-headed animals, both mouths are connected to the same stomach, Sonnenschein said.
Van Wallach of Harvard University's Museum of Comparative Zoology said We should live another 10 to 15 years.
"We expect the sale of We to be on the same level of demand as a priceless art object," he said.
The snake has been in the spotlight before. In 2004, a disgruntled City Museum worker stole We.
Authorities found the snake in the garage of the man's home in Illinois.
"He thought he was going to sell it," Sonnenschein said.
"The thing is, it's the only one in the world."
Source : DailyNews.