A two-headed snake named "We," the main attraction at the World Aquarium, has died.

The 8-year-old rat snake died of natural causes during the weekend, said caretaker Leonard Sonnenschein. Most two-headed snakes survive for only a week or two.

"It's terrible news," Sonnenschein said. "People come in every day and say: 'I'm here to see the two-headed snake."'

Sonnenschein said more than a million people have seen We over the years. Children were especially fascinated by the snake, wondering how two heads could coexist on the same body as We sometimes strained to slither in two directions at once.

"These kinds of questions helped spur the science spirit in children," Sonnenschein said.

Sonnenschein said he bought We from a snake breeder in Indiana for $15,000 when the reptile was just a few weeks old.

A taxidermist is preserving We's body, which should be back on display within a week, Sonnenschein said.

The World Aquarium, located inside the downtown City Museum, acquired We in 1999. Last year the aquarium tried to auction off the rare reptile to raise money for research and conservation programs, asking $150,000, but none of the bids was satisfactory.

The snake had both male and female genitalia, Sonnenschein said. The World Aquarium tried unsuccessfully to breed We with another two-headed snake last year, and had planned to try again this summer, aquarium spokesman David Isserman said.