Researchers studying invasive Burmese pythons in Florida recently came upon something they had never seen before: an 11ft python that had consumed an entire deer that weighed more than the snake itself.

The wildlife biologists stumbled upon the bloated snake in Collier Seminole state park. When they moved it, it began regurgitating a white-tailed deer fawn.

Biologist Ian Bartoszek told the Naples Daily News the fawn weighed 35lb; the snake 31.5lb.

“We were sitting there just trying to process that an animal this size could get its head around what turned out to be a deer,” Bartoszek said. “It’s surreal to see that in the field.”

Bartoszek said it was the largest python-to-prey weight difference he had measured.

Burmese pythons, which can grow to nearly 20ft, were brought to south Florida as pets in the late 1970s. Released into the wild, they have become a problematic invasive species.

White-tailed deer are an important food source for Florida’s endangered panthers, so the researchers are concerned the pervasive snakes could also affect the health of the big cats.

If the snake had been left in the wild, it would have digested the entire deer, Bartoszek said. The predator-to-prey size ratio, he said, stunned his team.

“It showed my team and myself what we were actually dealing with out there, what this python is capable of,” he told the newspaper.