A one-foot long corn snake was discovered in a garden while the homeowner was cutting the grass.
The snake was found in a garden on Manor Way, Whitchurch, Cardiff, on June 5.
The RSPCA said the snake has an injured tail and are trying to track down its owners.
RSPCA inspector Christine McNeil said: “The caller kindly asked around to see if anyone nearby had lost this snake, but has not been able to find out where he came from.
“It must have been quite a shock for the person who was gardening, but luckily this snake is okay and hopefully we can find out where he came from."
The snake is being treated at a vets and is being monitored before being transferred to a specialist exotic centre.
The corn snake is a North American species of snake which can live up to eight years and grow up to 5.5 ft.
The RSPCA said many of the snakes that officers are called to collect are thought to be escaped pets.
They collect more snakes over the summer months possibly due to the warm weather making the snakes more active.
It is also possible that this could be due to snakes having more opportunity to escape if owners take them outside to take advantage of the natural sunlight.
The RSPCA recommend that owners have their snakes microchipped at a vets.
Anyone with information should call the RSPCA on 0300 1238018.
