In “The Hangover Part II,” the sequel to the very successful what-happened-last-night comedy, the character played by Ed Helms wakes up with a permanent tattoo bracketing his left eye. The Maori-inspired design is instantly recognizable as the one sported by the boxer Mike Tyson, which is part of the joke. (Mr. Tyson makes an appearance in both films, playing himself.)

But S. Victor Whitmill, a tattoo artist formerly of Las Vegas and currently from rural Missouri, doesn’t quite see the humor. Mr. Whitmill designed the tattoo for Mr. Tyson, called it “tribal tattoo,” and claims it as a copyrighted work.

He has gone to Federal District Court in St. Louis to ask a judge to stop Warner Brothers Entertainment from using the tattoo in its posters or in the movie, which would amount to stopping the film from being released, as well as to demand monetary damages for what he calls “reckless copyright infringement” by the studio.

“Mr. Whitmill has never been asked for permission for, and has never consented to, the use, reproduction or creation of a derivative work based on his original tattoo,” argues the lawsuit, which was filed April 28, and will be taken up next week.

The suit isn’t frivolous, however, legal experts say. They contend the case could offer the first rulings on tricky questions about how far the rights of the copyright holder extend in creations that are, after all, on someone else’s body. They are questions likely to crop up more often as it becomes more common for actors or athletes to have tattoos and as tattoo designs become more sophisticated.

Warner Brothers responded on Friday in a brief to Judge Catherine D. Perry, stating that any delay in releasing the film would have huge economic costs. It also argued that there was no legal precedent for Mr. Whitmill’s assertion of copyright, saying he had put forward a “radical claim that he is entitled, under the Copyright Act, to control the use of a tattoo that he created on the face of another human being.”

Copyright and trademark law can be hard to understand intuitively — for example, the idea that you can “own” a photograph or a letter, but not own the right to reproduce its content. The example of a tattoo, where “ownership” means having it become part of your body, actually does little to clear up the matter.

The wrinkle in the “Hangover” lawsuit is that Mr. Whitmill has taken pains to leave Mr. Tyson out of it. “This case is not about Mike Tyson, Mike Tyson’s likeness, or Mike Tyson’s right to use or control his identity,” the complaint says. “This case is about Warner Bros. appropriation of Mr. Whitmill’s art and Warner Bros. unauthorized use of that art, separate and apart from Mr. Tyson.”

“One of the things that the copyright law gives you as an artist is control over your work — and he lost control here,” said Michael A. Kahn, the lawyer who is representing Mr. Whitmill. The complaint includes a photograph of the tattoo being inked and a statement from Mr. Tyson agreeing that “all artwork, sketches and drawings related to my tattoo and any photographs of my tattoo are property” of Mr. Whitmill’s business.

If a tattoo clearly violates copyright — say, exactly reproduces a Keith Haring drawing or an Annie Leibovitz photograph without permission — could a court order it removed?

The case gets more serious, according to Christopher A. Harkins, an expert on copyright and patents who has written the definitive law review article on the subject, when someone tries to profit from the copying — by, for instance, selling photographs of the infringing tattoos.

“I don’t see a court forcing someone to remove it, or wear a burqa, but they may not allow me to profit from that work that I had tattooed on my body,” he said, adding that it would be very unlikely that this action could delay “The Hangover Part II” from being released.

The range of material that individuals and businesses are seeking to get copyright protection for has only been expanding, often at the insistence of movie studios. Mattel has gone to court to assert the copyright of the face of its Barbie doll; fashion companies have been lobbying Congress to pass a law to protect unique, nontrivial new designs. And trademark, which is governed by different laws and is much more contextual, has been used by athletes and coaches to get a measure of control over terms like “three-peat” or “Revis Island.”