See also Brand X, Bland-Name Product, Disney Owns This Trope, You Wanna Get Sued?, Lawyer-Friendly Cameo, A.K.A.-47, Product Displacement, and Clumsy Copyright Censorship. Contrast Captain Ersatz, where the writers are trying to use an already existing character but can't.
This is one reason why a character might be Renamed to Avoid Association. The same reasoning behind many a Stealth Pun. We have a page about Trademarks if you're really interested in how they work and are used. However, certain uses are (at least in the United States) covered under what are known as Fair Use Laws. Efforts to have this listed as a violation of intellectual property are no doubt pending. If word gets out online, the original name may still be used by the fans. Better change the name before airtime, or you'll find yourself knee deep in the paperwork of a trademark infringement lawsuit. The character may not even be that well-known (or known at all) today. But there's a problem - someone else had the idea first. You have a great idea for a character name.
