Of late many business schools are offering MBA in Entrepreneurship. Master of Business Administration prepares one to run the company which was created by some entrepreneur or ones rich dad. Entrepreneurship is starting an enterprise from scratch where there is no set of rules already exist. Entrepreneurship is swimming in an uncharted water or going through the forest, where wild animals live- without knowing what is there. Entrepreneurship is taking a plunge and battle it out. Real entrepreneurs don't need MBA. People most probably start an enterprise after these MBA would otherwise have started the enterprise without even an MBA.
Entrepreneurs of course need financial and accounting skills and to write or understand a business plan. You can learn these by taking courses, while doing your undergraduate degree or attending some courses. Plenty of material also available in the web. Just to brush up these skills if you opt for a MBA you will most likely end up with a debt of $100,000 to $200,000 depending on the school you go, as well as the lost opportunity(1 to 2 years). To pay your debt most likely you have to work for others for several years and your Entrepreneurial dream might die by that time.
No company is going to become a million dollar business in one day. As the need arises you can learn things, while developing the enterprise. So unless your dad is rich do not go to MBA school to learn how to become an Entrepreneur. You do not need a MBA to be an Entrepreneur.