The beloved Super Mario character began as Nintendo’s commercial property, with merchandise following only after consumers associated the character with a commercial source. Tung Tung Sahur, a bat-wielding wooden drum that became one of the Internet’s best-known “Italian brainrot” memes, took the opposite path, going viral as an AI-generated meme without a firmly established commercial source. Now, a California federal court must decide if this and other viral memes can be protected by trademark or copyright law.

Indonesian artist, Noxa, prompted the character using generative AI in early 2025. It spread rapidly online and became a fixture of “Steal a Brainrot,” a hugely popular Roblox game. French licensing company Mementum Lab acquired rights to the character and sent the game’s developers a cease-and-desist letter. When licensing talks failed, the developers sued, seeking a declaration that Mementum cannot use U.S. copyright or trademark law against them, and Mementum filed a counterclaim for trademark infringement.

Copyright is an uncertain fit, since the U.S. Copyright Office has stated that merely prompting an AI model or system does not establish the human authorship requirement for copyright protection. Mementum has largely sidestepped the issue by issuing a covenant not to sue the developers for copyright infringement.

This leaves trademark law, which has no human authorship requirement but protects source identification rather than creative expression. The qualifying trademark question is not whether consumers recognize Tung Tung Sahur, but whether they see it as signaling a single commercial source. For a character that circulated freely as a meme before any licensing business existed, that may be hard to prove. The developers also point to the Supreme Court’s decision in Dastar Corp. v. Twentieth Century Fox Film Corp., which cautioned against using trademark law as a substitute for copyright.

The dispute offers a practical lesson for anyone working with AI tools or viral content: popularity is not ownership. Creators hoping to build a business around a character may want to document their human contribution early and use the character as a brand before the Internet decides it belongs to everyone. Lutzker & Lutzker can help with strategy at the early stages of brand creation. For further reading from our website on the topics discussed here, see the following insights and IP Bits & Pieces®: Due Diligence in Branding: A Cautionary Tale, How Trademarks Can Help Protect Artists and our Trademark FAQs.