Australian researchers Wednesday mourned the death of Cedric, a Tasmanian devil thought at first to be immune to a devastating cancer which is threatening to wipe out the species.
Cedric, who was born in captivity, survived for two years after being repeatedly injected with cells infected with the contagious Deadly Facial Tumour Disease (DFTD), raising scientists' hopes.
But after X-rays showed tumours in his lungs he was put down last week. He was six years old.
"He was especially important, because he did produce an immuno-response initially," Dr Alex Kreiss, of the Menzies Research Institute, told reporters in Hobart.
"We would like to remember him as the symbol of the fight against DFTD. There are many devils that die in the wild that don't have a name."
Kreiss said Cedric had provided information towards finding a cure for the fatal disease which affects Australia's largest meat-eating marsupial.
Some 70 percent of devils have already been lost to the infectious disease, which is spread by biting as the feisty creatures mate and fight over animal carcasses.
"Cedric has played an important part in helping us to understand more about the disease," Kreiss said.
"While this death is sad news, it is only one part of the puzzle toward developing a vaccine against DFTD."
Experts have been gathering healthy devils and breeding them in zoos for the past six years, developing an "insurance population" of 220, but the species was declared endangered in 2009.
The devils first came to prominence when their unearthly shrieks and grunts while devouring corpses of dead animals terrified European settlers arriving in Tasmania in the 19th century.
Some 150 years later, the Devil is best known by "Taz", a wild Warner Brothers cartoon character that now fronts the conservation campaign to save the species.