It's the stuff of science fantasy, but a respected American surgeon says that, within five years, he will be able to graft wings and tails on to human beings. Johann Hari on the bizarre world of radical plastic surgery

The TV sketch show Smack the Pony recently featured a hilarious scene in which a woman turned up at a plastic surgeon's clinic bearing a picture of a wolf. "I want to look like this, please," she explained, and people chuckled in living rooms across Britain. Across the Atlantic, however, there is a respected plastic surgeon who really is working on plastic-surgery techniques which could make us resemble animals in ways we can't even imagine today.

Dr Joe Rosen is not a quack. He works at the acclaimed Dartmouth Medical Centre, and has been a scientific advisor to Nasa. He is fond of making statements such as: "Human wings will be here. Mark my words." He believes in all seriousness that within five years he will be able to graft wings on to a human being's body. This is possible because our brains adapt to create neural maps for new body parts. When we have a limb amputated, our neural map of that limb gradually fades away; and if we gain a body part, our neural map expands accordingly.

"If I were to give you wings, you would develop, literally, a winged brain. Our bodies change our brains, and our brains are infinitely mouldable," Rosen has said.

Surgical techniques already in existence can be used to stretch torso fat and rejig rib bones to create a wing. Although no human would be able to fly, they would resemble angels and have full sensation in their new hanging, boned flaps of flesh. Rosen has designed blueprints. This is the new world of radical plastic surgery, where Rosen is Moses. He would not be content to settle merely for wings either. He has been working on cochlear implants to enhance human hearing (a procedure which the US military has shown interest in, raising as it does the prospect of super-human soldiers), and even tails.

In a conference speech last year, Rosen asked: "Why do we only value the average? Why are plastic surgeons dedicated only to restoring our current notions of the conventional, as opposed to letting people explore, if they want, the possibilities?" He says it is only our "Judaeo-Christian conservatism" that is holding us back.

If the medical-ethics board allowed it, Rosen insists he would carry out these procedures. And, as the case of Severino Antinori, the Italian doctor hell-bent on cloning a human, shows, once the technology and the will to experiment exist, it is very hard for even the most overwhelming ethical qualms to block these actions. Sooner or later, Rosen's plans will be put into action: just like the mouse with an ear on his back, one day soon a winged human will force us to re-examine the fundamentals of human life.

So it's time that we started to ask serious questions about the people who will be the guinea pigs in the radical plastic-surgery revolution. Put bluntly, who the hell would want wings or a tail? We can perhaps find answers by looking at people today who have already changed their bodies in radical and seemingly unnatural ways. Jim Rose, the head of a gross-out travelling circus or "freak show", has considerable experience of people who drastically alter their bodies. A former colleague of his known as Enigma now has horns. Seriously.

Enigma's horns are implanted deep into his skull. They are made of coral, which is recognised by the body as similar to bone. Each year he has progressively larger coral implants because it is taking time for his skin to stretch. He only gave up on his dream of having jewelled eyebrows embedded into his face when doctors told him forcefully that having transdermal implants near hair follicles was extremely dangerous.

So Rose's friends and colleagues such as Enigma are exactly the kind of people who will be first in the queue for Rosen's new operations. He says that, "Rosen is talking their language. I've worked with people with split tongues because they want to be like lizards, people who want to look like cats. I've lived with these people on the road for years, and believe me, they're very interested in operations that could give them tails or wings."

He has interesting insights on the psychology of people drawn to this kind of procedure. "If there's one thing that the outrageously altered have in common, it's an incredible need for attention. Most of them in their past have felt overlooked, usually by a parent. That gives them a mindset that's like, 'I will not be ignored.' Because of their desperate need for attention, they're usually happier after they've been altered [for example, by being covered with tattoos]." But the attention they receive "almost always causes this unbearable kind of eg