Film and television works are copyrighted, and their rights are enjoyed by the producers. Of course, characters are also protected by copyright.
If someone uses the image of a movie or TV character to register a trademark, it infringes the copyright of the producer. The Trademark Law stipulates that the application for trademark registration shall not damage the prior legal rights of others. At present, similar cases show that the names of well-known comics are mostly protected by "prior commercialization rights". If you directly choose them as your own trademarks for registration or use, it will easily constitute infringement.