Scotland's animal welfare charity was called to rescue the unusual lizard after a resident of Neilston Avenue in Pollock made the discovery on Wednesday afternoon.
The water dragon, who has been nicknamed Hulk, is now in the care of the Scottish SPCA's Lanarkshire Animal Rescue and Rehoming Centre in Hamilton.
Animal Rescue Officer Joanna Boyle, said: "Chinese water dragons can be kept as pets so I think it's likely Hulk has escaped from home.
"The man who found him has reptiles of his own so he wasn't fazed at all when he spotted him running around in his shed.
"I took Hulk to a vets as he appeared to have a sore leg and they confirmed it is infected, possibly a result of something falling on top of it.
"Hulk had probably gone into the shed to seek some shelter and I don't imagine he had been straying for long as he wouldn't have been able to survive in the wild.
"He's a rather unusual pet so we're hoping someone will recognise him and come forward.
"If not, we'll find him a new home with a knowledgeable owner who will be able to meet all his needs."
Anyone who recognises Hulk is being asked to call the Scottish SPCA Animal Helpline on 03000 999 999.