DALLAS, Texas (AP) -- Allen Falkner's tongue is just one of his unusual features.
It is split down the middle, and when he sticks it out, it looks like a two-pronged snake tongue.
The alteration -- along with others -- to the 36-year-old Dallas man's body might appear shocking, but they're standard for people in the growing trend known as body modification.
Over the last decade body mod has been growing steadily, attracting more followers now that tattoos and simple piercings are more mainstream.
"I think there's definitely more and more interest all the time," said Falkner, owner of a Dallas tattoo and piercing shop called Obscurities. Extreme body modification features a wide range of alterations, including some that are illegal in Texas and elsewhere.
Some people get horns implanted on their heads. Some install magnets in their hands, creating a "sixth sense" for feeling magnetic fields. Others remold their ears to make them pointy.
The alterations are far from mainsteam, and far from regulation as well. The underground nature of the trend has raised concerns among some health officials as well as among more traditional body artists.
But the demand for extreme body modification is growing.
"People want, I think in general with society -- especially the younger sect -- to be different," said Luis Garcia, international liaison for the Association of Professional Piercers, which takes no official stance on the modifications. "It's not different anymore to have your navel pierced."
Falkner did his work himself, experimenting with various methods and instruments that included scalpels and string. Already sporting multiple tattoos and piercings, he said, he further modified his body for aesthetic reasons, and in part just to see whether he could.
Falkner runs several Web sites dedicated to the topics and said he gets e-mails all the time from people interested in modifying themselves.
Likewise, Garcia said people often ask for implants, split tongues, scarring or other procedures at his shop in Philadelphia.
With television shows profiling tattoo shops and increasing numbers of piercings in the mainstream, more people are searching for procedures for the "one-upping factor," Garcia said. "I've had people as young as 15 inquire," Garcia said, noting that he won't accommodate their requests for legal reasons.
And neither will most established tattoo and piercing shops. Extreme modifications are banned in a handful of states, including Texas and Delaware, which specifically prohibit tongue splitting. But similar procedures usually fall under a legislative gray area.
Many artists also won't do them for fear of lawsuits or insurance fiascos, Garcia said. "It's definitely underground," he said. "Any person that does implants out of their shop is taking a big risk." He cited health consequences as the main hurdle to widespread practice.
Garcia had his transdermal chest implants -- a type of implant anchored under the skin but protruding outside -- removed after a few years. He got "a couple of infections that were an annoyance and just a constant irritation," he said. Falkner also removed some implants from his wrist because they constantly banged against things or got in the way.
Doug McBride, spokesman for the Texas Department of State Health Services, said underground and non-professional alterations could end in problems. "If this is being done by unqualified people using equipment and facilities that are not sanitized or sterile, then you're going to have that increased risk of infection," he said.
Bill Johnson, secretary of the Alliance of Professional Tattooists, agreed that more extreme and experimental modifications are probably not the best idea. "My personal view is, it's just too dangerous," said Johnson, whose group officially takes no position on the practice.
Many modification enthusiasts don't consider all the health ramifications, experts said. Garcia tells interested people to "think about it -- because when they do need to come out, it's not as easy as putting them in."
But many modifiers say they don't think health or legal hurdles will curb the trend. They said the drive to be different and creative will keep pushing people to embrace more extreme modification.
"It's evolving to the point where sometimes I kind of scare myself at thinking what will be next," Garcia said.