The six-year-old leopard tortoise is more suited to the savannas of Africa than the gardens of Hartlepool, and can only live for up to two weeks in the English climate.

Sabah Parrott and her three young children are now desperately hoping that their pet of three years, called Shell-be, will be returned home after she walked out of their garden on Saturday.

They are asking for anyone who lives around the West Park area of Hartlepool to check their gardens, sheds and garages as the eight-inch long animal will look for a quiet spot to settle and hibernate.

Sabah, who lives in Coatham Drive, said: "She usually lives in a vivarium to keep her warm, but we often let her out in the garden on sunny days.

"But on Saturday afternoon she has trotted off and we lost her. They can move a lot faster than people think, and could have gone quite far.

"The vet said she will probably hibernate, which they are not supposed to do as they are tropical, and will only have two weeks before she dies outside.

"The kids love her and she feels like part of the family so we just want her back.

"I turned off the vivarium lights the other day and it made me cry, that's how much we miss her."

Sabah's children, Britney Ali-Parrott, nine, Sophie Ali-Parrott, four, both West Park Primary pupils, and Nathan Ali-Parrott, three, have been trying to entice Shell-be home by putting melon and lettuce out in their garden.

"They all think she is having fun with the wildlife and playing, but it is very serious as she won't have long outside," added Sabah, a law student at Teesside University.

"I have phoned everyone I can to help, including the police and the RSPCA, but it's really down to people looking and hoping that someone spots her."

Leopard tortoises can live for 100 years and grow up to 18in long and weigh up to 40lbs.

They are grass grazers and are defensive natured, being more likely to retreat into their shells than act aggressively.

If you find Shell-be, or have seen her, contact Sabah on 07543190511 or (01429) 283616.