The RSPCA are now investigating to try and trace the person responsible for abandoning the pet in a layby near the Widdrington Inn, on the A1068, on Sunday morning (November 14).
The walker spotted a cardboard box discarded nearby with some vegetables in it. It is believed the reptile was abandoned in this box and had then escaped.
A local vet attended the scene and took the reptile for treatment. The iguana was found to be in good condition but was cold and needed warmth,
Now RSPCA inspector Lucy Green is investigating and keen to trace the person responsible for abandoning the reptile.
She said: “It was really lucky that the iguana was spotted as it was quite a remote location and would not have survived long in the cold.
“I just cannot understand how someone can dispose of their pet in this way.
“Very sadly, many people buy exotic pets without thinking through the responsibility first and with little or no idea of how difficult they are to care for, which as a result can lead to them being abandoned in a callous way like this. Ultimately it is the animal that suffers after the novelty wears off.
“The RSPCA sees many exotic pets just being abandoned and left for dead, or given up, because their owners have got bored of them or don’t know how to care for them properly.
“We do find that people take on exotic animals like reptiles without researching their needs or having any idea of how to care for them properly. They then end up suffering; becoming injured, sick or even dead.”
Lucy is hoping someone may recognise the pet - which was left in a cardboard box used to package a fish tank - or may have seen something suspicious that morning.
She added: “I am concerned that whoever had the iguana may have other pets like fish and am worried about their ability to care for them.”
The iguana is now in the care of a specialist reptile keeper.
Anyone who has any information about the iguana should contact the RSPCA on 0300 123 8018.