The school's compliance office has issued cease and desist notifications—with a great headline, by the way—to the makers of several really cool T-shirts, even though the shirts don't mention LSU or Tyrann Mathieu by name. The reason?
Apparel or paraphernalia including the phrase "Honey Badger" accompanied by the number 7 or the individual's name or any other variation thereof (e.g., TM7, TM, HB7, etc.) is prohibited. Because it is a recognizable nickname, "Honey Badger" is considered a likeness of Tyrann Mathieu under NCAA regulations.
LSU was also helpful enough to link to the NCAA regulation in question, which states:
If a student-athlete's name or picture appears on commercial items (e.g., T-shirts, sweatshirts, serving trays, playing cards, posters) or is used to promote a commercial product sold by an individual or agency without the student-athlete's knowledge or permission, the student-athlete (or the institution acting on behalf of the student-athlete) is required to take steps to stop such an activity in order to retain his or her eligibility for intercollegiate athletics.
Just another reminder that the NCAA has complete control over student-athletes. Interestingly, the regulations make a notable exception for the private use of photographs sold by an individual or news agency. And it's not like Mathieu has any of those out there or anything.