A rare, two-headed snake that was found a few months ago in a Virginia yard has died.

Experts said it wasn’t immediately clear what caused the snake to die, but snake keepers who specialize in caring for bicephalous snakes said it was “particularly challenged because of how far down the spine was fused.”

The copperhead was about six to eight inches long and was about two or three weeks old when it was found. It first showed up in a yard in Woodbridge, Va., in September.

A photo was posted to the Facebook page of a wildlife expert and the snake’s story quickly became a social media sensation. The snake was also a notable find among scientists and biologists who called it a rarity in the world of herpetology because two-headed snakes don’t often happen in the wild. Most of those that are alive have been bred in captivity.

JD Kleopfer, the state’s herpetologist, called it an “exceptionally rare” find at the time. In his three decades of studying snakes, he said he’d never seen anything like it. “This is an extraordinary animal,” he said, calling it “a Ringling Brothers and Barnum & Bailey Circus kind of moment.”

The fact the snake had survived in the wild was also unusual because experts said it was at high risk of being eaten by a predator. The snake was taken to a wildlife refuge center and there was talk of it being donated to a zoo.

Earlier this week, Kleopfer broke the news of the snake’s death on social media. He said, “sad news. Our little buddy peacefully passed away last week.” He went on, “no apparent reason, just found dead one morning.”

Kleopfer explained that he had talked to snake keepers who specialized in two-headed snakes and they said that sharing a body puts added stress on the reptile, particularly the spine “when the heads want to move in different directions.”

Experts had a chance to look at the two-headed snake and found it had several notable features. It had two heads but one heart and one set of lungs. Both heads appeared to have venom. It also had two spines that fused together to have two heads.

At the time it was found, Kleopfer said he didn’t want to name it for fear he’d jinx its survival.

Now Kleopfer said the snake’s body will be donated to a museum, but he did not specify which one.

His Facebook post ended with “RIP.”

Some commenters wished condolences and one called Zachary Tyler wrote, “damn. :( I would totally go to a funeral if there was one.” One person asked what were the chances of finding another two-headed snake in the wild?

Kleopfer responded, “Slim to none.” But he noted, there was one found last month in a couple’s yard in Frankfort, Ky.