A metre-long white snake with red eyes was spotted on the front drive of a house in Chalford, Westbury, by retired headteacher Anthony Sadler.
Mr Sadley, 71, the former head of St George’s Primary School, Warminster, said: “I did not know if it was real or whether it had been put there.
"I phoned Wiltshire Wildlife Hospital because I did not know if it was venomous.”
By the time staff from the hospital had arrived on Sunday afternoon it had slithered off.
Mr Sadler said: “It could still be there for all I know.
"Possibly it could be a corn snake or a blizzard corn snake from North America, which are totally white with red eyes and very little to no visible pattern."
Marilyn Korkis, supervisor at Wiltshire Wildlife Hospital, Salisbury, said: “They are quite harmless. Many have been kept as pets that have escaped.
“They should not be cornered because they can hiss and appear threatening.”