Shocked walkers stumbled across a nine-foot-long boat constrictor during a ramble in the Welsh countryside on Saturday.
Sadly the female snake, spotted stretched out to her full length on a path in Erddig Park, Wrexham, was dead.
Pictures of the reptile were circulated online, alerting zoologist Chris Wright.
He said: “On Saturday night I had a phone call saying a large snake had been found and I saw the pictures on Twitter.
“Now usually when people talk about a big snake they just mean a large grass snake but this is a 9ft long boa constrictor.”
Kevin Harvey found the snake as he walked with his neighbour David Evans.
He said: “It was incredibly long. It was easily as thick as my leg, and so, so, heavy.
“We were so surprised to stumble across it and we poked it with a stick to see if it was still alive."
Wright has since buried the snake, which he believes died as a result of the cold.
He added: “The snake was a female and an absolute beauty. I have no indication of age but she was quite well fed.
“It is such a shame. She had either escaped or more than likely had been cruelly dumped by someone.
“It happens quite often unfortunately. It is most likely someone has dumped it and unfortunately it has been killed.”
An RSPCA spokesman told the BBC: "In general people need to think carefully before taking on a pet like this."
The boa constrictor is a species of large, heavy-bodied, non-poisonous snake.
It is a member of the family Boidae found in North, Central, and South America, as well as some islands in the Caribbean. Its prey includes a wide variety of small to medium sized mammals and birds.