Two 10ft-long pythons, which are believed to have been abandoned, were rescued within days of each other in Cambridgeshire.
Another reticulated python, which are native to southeast Asia, had been discovered nearby four days earlier.
The RSPCA urged people to stay vigilant in case there were more.
2 reticulated pythons 🐍🐍 found days apart of one another in the same location near Conington, Cambridgeshire. We thought the 1st had escaped but since finding the 2nd, can only assume they may have been dumped 💔. Any info please get in touch with us. @RSPCA_official 73 pic.twitter.com/XYPLo3xoxu
— RSPCA Frontline (@RSPCA_Frontline) September 1, 2021
The charity added that it had thought the first snake had escaped its owner. But after the second was discovered rescuers said it was likely both were abandoned.
The first had a minor health condition, while the second was "extremely cold" and thin, the RSPCA said.
Both snakes are now recovering.
RSPCA Inspector Justin Stubbs said: "It is really concerning to think that someone has kept these pythons, then might have decided to abandon them in this cruel and callous way.
"I only hope that there are no more on the loose. As well as the dangers of low temperatures, harvesting in the nearby fields could pose a real hazard to any snakes left out there."
Reticulated pythons, along with the green anaconda, are the largest snakes in the world and one of the only species known to prey on humans.
Mr Stubbs added that he had rescued the first snake from a tree near St Ives on Friday in a scene that was "reminiscent of the Jungle Book".