You do not need to copyright your comic book since it is already protected by copyright law as soon as you create it. Copyright is a form of legal protection that automatically applies to original works of authorship, including literary, artistic, and graphic works like comic books. However, registering your copyright with the U.S. Copyright Office can provide additional legal benefits and protections, such as the ability to sue for infringement and the right to statutory damages in the event of infringement. Registering your copyright also creates a public record of your ownership of the work. If you plan to publish and distribute your comic book widely, it's generally a good idea to register your copyright. The registration process is straightforward and can be done online through the U.S. Copyright Office website. The cost is relatively low, typically ranging from $35 to $65, depending on the type of work and the method of registration. Keep in mind that copyright law can be complex, so it may be a good idea to consult with an attorney or a copyright specialist to ensure that your rights are fully protected.