Can I Name My Company MellowStarbucks? SuperNike?

Dear Rich: Is it legal to create a new company name by adding a word to an existing company name ? (I was unable to Google an answer anywhere). Some examples of what I'm talking about are Supernike, Mellowstarbucks, and Smoothmonster (monster energy drink). The short answer would be "No." We're not sure what Google search terms you used but we located a lot of material online explaining why it's not a good idea to borrow and modify a famous company's name. You can also peruse this book or this book (both by the Dear Rich Staff) on the subject at Google Books. 

The Conned-Sumer

The main principle at work here is called likelihood of confusion. If consumers confuse Supernike with Nike, then you are infringing. In addition, you cannot dilute famous trademarks. Of your three examples, "smoothmonster" seems the least likely to confuse since "monster" has a common meaning not necessarily associated with commerce. But based on the litigation history of Monster Cable (not Monster Energy Drink or Monster.com), you can expect a hassle over that choice. (If you plan to use these names solely as your corporate name but not as a trademark for your company or your company products or services -- for example, simply as the name of your LLC -- your uses may go unnoticed.)  Otherwise, your plan to "prefix" your way to brand identity is not going to fly and will only lead to a mailbox full of cease and desist letters.