A slimy, six-inch hermaphrodite with a taste for raw meat and an unmatched capacity to breed sounds like the stuff of science fiction. But the Giant African Land Snail is one of a growing breed of alternative animals threatening to topple the humble cat and dog as Britain’s most wanted pets.

When a Californian "lifestyle pet company" announced last month that it had developed the world’s first hypoallergenic cat, images of Joshua, its anti-sneeze poster kitten, circulated the world’s media. In Britain, for decades the domain of loyal retrievers and tabbies, most observers raised an eyebrow at the £4,000 feline, muttering "only in America". But Allerca, the firm that bred Joshua, says it has been inundated with enquiries from 85 countries, including the UK.

Increasingly, Britain’s 30 million pet owners are seeking out the exotic and glamorous. Inspired by the late crocodile hunter Steve Irwin, as well as Paris Hilton- style socialites, a new generation of animal lovers is ditching hamsters for dragons and spaniels for Chihuahuas.

According to the Association of Pet Food Manufacturers, the £4bn industry’s source for ownership figures, cats and dogs remain our best friends, with an estimated population of 10 and seven million respectively. But their ascendancy is under threat.

The British Federation of Herpetologists believes there are already more reptiles than dogs in UK homes and while the number of canines began a steady decline 10 years ago, sales of snakes, lizards, spiders and snails continue to rocket with a five-fold increase in the past 10 years.

Steve Irwin, whose death in September at the barb of a stingray shocked the world, is credited by many with dispelling myths that paint vertebrates as slimy, sinister creatures best confined to zoos.

Top of the exotic chart is the corn snake, a fire-coloured but human-friendly species that can live for 30 years. But the buzz in the country’s growing number of exotic pet shops surrounds the bearded dragon, a two-foot lizard that thinks it’s a dog.

Spiny tails, scales or a surfeit of legs might tick the boxes for an increasing number of pet owners, but it is not all doom and gloom for our furry friends – at least not for certain breeds.

Hardly exotic and by no means hypoallergenic, the humble moggie is facing stiff competition from glamorous pure breeds such as the Maine Coon, the Bengal and the striking Norwegian Forest Cat.

The ubiquitous Labrador faces similar peril in dogdom. The Staffordshire bull terrier has replaced Pit bulls and Rottweilers as the must-have tough mutt in the nation’s housing estates and has risen to fifth on the Kennel Club’s top breeds list.

Yapping for attention further down the table but climbing fast is the inimitable Pug. The bulging-eyed bundle of energy featured in the hit film Men in Black has joined the Chihuahua, Shih tzu and Bichon Frise on the list of dogs to be seen with in Britain’s posher postcodes.

The Lounge Lizard

Perhaps better suited to the sunbaked bush of its native Australia, the Bearded Dragon is increasingly finding itself at home in Britain’s garages, front rooms and bedrooms. The UK’s reptile population has exploded from 1.5 to 6 million in the past 10 years. The Corn Snake, Leopard Gecko and Bearded Dragon account for most sales, but among reptile fans and converts, the Dragon is earning a special reputation as a playful but undemanding alternative to more traditional pets.

"I used to have cats, but I prefer my dragons because they show more interest," says Sam Davies, aged 15. "They’re more like a dog – they scratch the glass of their tank when I get home and want to play. They recognise me and form a really strong bond."

Sam got his first dragon four years ago. He named her Halo and soon introduced her to his second Bearded Dragon, Bob, so-called because of the way he nods his head up and down to show everyone who is boss.

"Bob’s mad when I get him out. He runs around the carpet really fast and then stops to bob his head," says Sam, who also keeps two Corn Snakes at his family’s Hertfordshire home. "When it’s warm I’ll take him out into the garden and he basks in the sun with his mouth open. If we’re driving along in the car he likes looking out the window."

With a taste for live locusts and a demand for a tropical environment, dragons may not appear to be ideal pet material, but Mark Amey, herpetologist and owner of Ameyzoo, an exotic pet shop in Hertfordshire, thinks reptiles suit the hectic schedule of the modern pet owner.

"These days people don’t have time for dogs and cats," he says. "But with a Bearded Dragon you can go to work or school and not worry about it until you get home, when it will play with you. Then at night it goes back in its tank and goes to sleep."

But Amey, who has already sold more dragons this year than in all of 2005, warns prospective owners to think carefully before buying. "It’s a huge responsibility to take on any animal as a pet," he says. "But considering an exotic animal is an even more serious responsibility."

Like many other reptiles, Bearded Dragons need a special tank which is equipped with an ultra-violet light bulb to replicate the harsh Australian sun the species is accustomed to. They also have special diets – locusts, cockroaches and chicory are all on the menu, though spinach is a no-no – but compared with some other exotic pets they are easy to keep.

And Sam says Bob and Halo have an irresistible charm that has won over his family and friends, all of whom were initially sceptical.

"Sometimes when we’re playing in my room I’ll look up at his tank," says Sam. "Bob will be just standing there, poking his head round to watch us. Some of my friends weren’t sure about them at first but after they hold them they’re amazed. Now they all want one."

The It-Dog

No self-respecting socialite walks down Rodeo Drive or the King’s Road without a Chihuahua lodged in a Gucci handbag or at the end of a pink, bejewelled lead – but now the market for fashionable pooches is booming among the less well-heeled too. Yellow Pages has recorded a 93 per cent increase since 2001 in the number of dog- grooming businesses it lists (Exeter is a hotspot, apparently), and breeders of the Pekingese and Bichon Frise are struggling to meet demand.

But one dog is attracting special attention thanks as much to its convenient size as its bizarre looks and mischievous personality. The wrinkled face, upturned nose and bulging brown eyes of the Pug give it a fixed, quizzical expression that repels and delights in equal measure.

Candace Maher-Walsh, a Manhattan restaurant consultant who moved to London with her British fiancé four years ago, is smitten. "I first fell in love looking at pictures of them back in New York," she says. "I just adore their faces."

Soon after Maher-Walsh, 35, married Graham in 2002, the couple took delivery of Louie and Zucchini. "Zucchie’s a bit of a whacko," says Maher-Walsh. "He barks at aeroplanes and recently started to chase buses and cars. He’s also totally obsessed with me. If I’m cooking at the stove, he’ll lie on my foot and fall asleep, but if I get up f and go to the fridge or something, he’ll get up, move and lie on my foot again."

Used to the glut of pet boutiques that line the streets of Manhattan, Maher-Walsh was dismayed to find nowhere in London that could kit out her puppies. When she considered a return trip to Manhattan, her husband suggested opening her own shop. Now Pugs and Kisses, in west London’s smart Parsons Green, does a roaring trade in luxury pet accessories and spa treatments.

The store is no longer alone – Maher-Walsh says four new pet boutiques have opened in London just since the summer – and Britain’s pampered pooches are being showered with ever more expensive accessories.

"Recently people started coming in asking for Swarovski crystal collars," says Maher-Walsh. "When they find out they cost about £250 for a collar and lead, they look surprised."

Maher-Walsh sometimes dresses Louie and Zucchie. "I’ve just reserved a French- pink collar with black brocade in velvet that I’m really excited about," she says. "English people are usually quite practical about dressing their dogs because it’s cold here – but in the past year people are starting to buy T-shirts just because they’re cute."

The Kennel Club has recorded a 140 per cent rise in Pug registrations since 2001, with more than 2,000 last year. Maher- Walsh has noticed the trend: "There is definitely a new younger generation who are buying Pugs. Just in Parsons Green I’ve noticed 10 more in the past year."

So popular is the breed that Maher-Walsh often receives invitations to join other Pug devotees at special picnics in London’s Battersea Park. She says: "We all meet and bring food and blankets and set up a special picnic for them, with champagne and hors d’oeuvres for the adults."

The Must-Have Mollusc

Children’s fascination with creepy-crawlies and slimy snails is nothing new, but talk in the nation’s playgrounds increasingly is of a snail so big you can hear it breathe. To the uninitiated, the Giant African Land Snail (Gals) is a freak of nature. Imagine a garden snail, then scale it up to the size and weight of a melon and you’re almost there.

A common pest in its native east Africa due to its huge appetite for crops, the Gals is banned as a pet in many countries, including America. But in the UK they are 10 a penny – sometimes literally – with many owners even giving them away. Each snail lays up to 300 eggs in one go, so pestered parents need not look far to get their hands on a monster mollusc.

Ellis Deacon, a site assistant and father of four children aged 18 months to 11 years, first heard about the Gals from a school mum. "I thought nothing of it until last summer when I got fed up with the kids bringing in snails from the garden and asking to keep them," he says. So the family welcomed Gary and Spongebob, two adult Achatina fulica, to their Eastbourne home. "When my wife first brought them home I wasn’t sure," says Deacon. "It’s almost like you’ve been shrunk down in size, they’re so big. But they’re actually quite cute, believe it or not."

Within a few weeks, Gary and Spongebob had mated. Gals are notorious sex-maniacs, and foreplay is a slippery union that can last for hours. After gentle kissing and caressing of head and tentacles, all four sets of genitals become swollen (each snail has both a penis and vagina behind its head). The aroused molluscs then combine in a passionate sex lock and, at the point of climax, each fires a centimetre-long dart into its partner’s vagina. Snails can hoard sperm for up to a year, fertilising at will. After about two weeks, 200 pea-sized eggs were lain. "I didn’t have the heart to get rid of them," says Deacon. "And the kids were fascinated as they watched them hatch."

A quick web search revealed a market for Gals on Ebay, and soon Deacon had set up an online store. Through The Snail Trail he recently sold a batch of 80 at 65p each, but now has his sights set on bigger things: the Ghanaian Tiger Snail, the world’s largest – one specimen caught in the wild was 15 inches (38cm) long.

How Gary and Spongebob will cope with the Tiger Snails remains to be seen, but Deacon may see a rise in his pet food bill. Gals have healthy appetites, munching their way through as much fruit, vegetables and dog biscuits they can get their slimy suckers on.

Deacon targets his Gals at schools; he says they inspire children to learn about nature. "The thing with snails is they’re so fascinating," he says. "When the children’s friends come round they think they’re horrible at first but when I get them out, they stare at them. It’s really interesting to watch them mating and eating. My five-year-old, Lewes, loves to hold his snail. You can feel its mouth rasping at your hand and hear it chomping its food." f

The Tough Mutt

Bred in the 18th century to fight bears and once used to bait lions, the Staffordshire bull terrier has never managed to shake off its hard-as-nails image. The Staffie’s solid looks and vice-like jaw make it the dog of choice for a certain breed of urban youth – "tough" young men who gather in parks and housing estates across Britain, their loyal Staffies straining at chainlink leads and studded leather collars. Last year there were reports from Hull of a Staffie called Asbo.

John Kilgannon, a plasterer from Peckham, south London, is walking his terrier, Paddy, in a park popular with gangs of youths and their Staffies. One teenager stands by as his dog, Bully, hurls itself into a nearby pond, ducks scattering before it. Only when a community police officer approaches the group do the young men control their animals.

Kilgannon, 31, is unimpressed. "I think the dogs should be taken off them straight away. They’re good animals. They have a reputation but it isn’t fair because you get good and bad in any animal, even humans. It’s the way you bring them up."

Despite its reputation, the Staffordshire is renowned for being child-friendly, earning it the nickname "nanny dog". Kilgannon says his children, Millie, six, and Charlie, three, would be lost without Paddy. "They love him," he says. "They drive him crazy pulling him and jumping on him. They think he’s a horse sometimes but he never reacts to anyone."

Kilgannon is part of a growing band of Stafford owners seeking to reclaim the breed from a minority of unscrupulous breeders and owners. In the darker corners of Britain’s towns and cities some people rear or steal the animals for illegal dog fights. Others simply neglect or abandon them. Last year Battersea Dogs and Cats Home took in over 1,500 Staffies, more than any other dog including mongrels, and 80 per cent more than in 2000.

Earlier this year Paddy was himself the victim of the alarming rise in Staffordshire "dognapping". When Kilgannon popped into a high-street shop, he came out minutes later to find Paddy stolen. After plastering Peckham with posters, he received an anonymous call a week later and paid a £250 ransom for his beloved dog. "When he came home he wouldn’t eat or anything," says Kilgannon. "I think he had the hump with me because he thought I’d just left him. It took him about a week to get back to his normal self."

Phil Buckley, Kennel Club spokesperson and Staffordshire owner, says the actions of some people unfairly tarnish the breed. "It’s the macho idiots who get them for the wrong reasons," he says. "They either train them incorrectly or to be aggressive. Very few dogs are born that way."

Kilgannon agrees. "Some people are scared of them but they shouldn’t be," he says. "Paddy’s much loved where I live – everyone knows him and all the kids come and say hello to him, not me. All he wants is to be loved."

The Giant Moggy

According to Scandinavian folklore, the Norwegian Forest Cat was a Viking’s best friend but, lagging some way behind its owners, the cat reached our shores just 20 years ago. Since then the "Fairy Cat", as some folk tales call it, has become one of Britain’s most desirable moggies.

Admired for its ethereal grace, lush winter coat and flowing, bushy tail, the "Wegie" is the fastest-growing breed in the country, according to the Governing Council of the Cat Fancy, with registrations up four times in the past five years.

Ali Ross discovered the Forest Cat when her silver tabby, Kenny, was run over three years ago. "My husband, Steve, wanted a big furry handsome cat, and that’s what we got. We’ve never looked back," says Ross. Her first Wegie, Ellwood, is now one of seven that occupy her north-east London home. "Many people haven’t heard of the Norwegian Forest Cat but when they do they become besotted. They have incredible personalities – they’re very affectionate and they’re also great around kids," says Ross, who seven weeks ago welcomed a baby daughter, Carys, to her menagerie.

Male Skogkatts, to use the breed’s native name, can weigh in at two stone, making them pretty robust animals. It has adapted over centuries to the harsh climate of northern Scandinavia, where its thick, waterproof coat kept it warm as it stalked the snowbound forests, plucking fish from icy streams. Its wild heritage and otherworldly appearance combine with a cool but gregarious personality that has breeders drawing up long waiting lists.

Kate Healing, a Forest Cat breeder and Secretary of the Norwegian Forest Cat Club, has noticed a surge in interest, with some customers prepared to wait up to a year for one of her £300-£500 Wegies. But she warns that as their appeal grows, so does the number of abandoned animals. She says: "Ten years ago we’d get one rescue cat in two years, but now it’s about one a month."

Healing says the Forest Cat’s hardiness is one reason for its increasing popularity. "They’re a natural breed and haven’t developed any of the genetic problems that afflict other breeds," she says. But the Wegie’s playful personality is what hundreds are lining up for. "They’ll even retrieve toys and go for walks in a harness," says Healing. "Kids love them because they look quite wild but are actually very gentle in their nature."

"Wegies can be mischievous too," says Ross. "Dewi likes ‘helping’ me in the garden when I’m planting by digging the plants up again. His brother Dom will get under the sheets and hide when I’m making the bed. He doesn’t seem to realise that it’s hard to miss a lump the size of a medium-sized dog in the middle of the bed."