A 7ft-long snake with an appetite for small animals is thought to have escaped from a house in Hull.
Ellie last had a meal of rodents five days ago
The five-year-old Common Columbian boa constrictor is called El-Diablo (The Devil) after its red tail and is known as "Ellie" for short.
He usually lives in a vivarium at a house in Wharncliffe Street but owner Paul Kemp could not find him on Monday.
Mr Kemp has "ripped the house apart" but not managed to find him and thinks he may have escaped via the toilet.
The snake has lived in the vivarium for more than four years and has never escaped before.
Mr Kemp has kept snakes, most of which are unwanted pets, for nearly 20 years.
The boa constrictor is not a danger to humans - but it will eat small animals such as guinea pigs. People living in the area are being urged to ensure their pets are kept secure.
Mr Kemp told BBC News: "I usually feed him small rodents. He feeds every 10 days or so and last had a meal five days ago.
"I took him in as an unwanted pet. Boas can live to between 20 and 30 years of age.
"I am concerned in as much as he needs heat in order to live. He is naturally cold-blooded and must have some warmth for his blood.
"I hope he has found somewhere warm to curl up."