A woman got the "fright of her life" when she woke up to find a 3ft snake sharing her bed.
The royal python, believed to be an escaped pet, had curled up next to her as she slept.
She made a desperate call to the RSPCA for help on Monday morning after jumping out of bed, rushing out of her bedroom and closing the door.
But by the time animal collection officer Jill Sanders arrived at her flat in Kensington, west London, the snake had slithered away.
"The poor resident must have had the fright of their life waking up to a snake in their bed," she said.
"They jumped out of bed and closed their bedroom door to contain the snake but, when I arrived, I couldn't find where the python had slithered to.
"I left my details and told them to contact me as soon as they saw it again."
The python was finally caught by Ms Sanders in the corridor the following evening when she was called back to the flat.
The RSPCA does not know how it got in but believes it must have escaped from its owner nearby.
The animal welfare charity says it collects more snakes in the summer as they have more energy in the warm weather and are good escape artists.
Ms Sanders added: "We would always recommend owners invest in an enclosure suitable for the particular species and that the enclosure is kept secure, and locked if necessary, when unattended.
"Reptiles, particularly snakes, can be extremely good escape artists and will take the opportunity of a gap in an enclosure door, or a loose-fitting lid."