Mugenmidget
Mugenmidget is a former member of Mario Fan Games Galaxy who was banned after the Phisherman Fiasco in 2006. Before his removal, he was well-liked by most members - but not administrators - and was bright, cheerful, and clever in an odd way in most of his posts.
Mugen's Many Masks
Mugen often visited the boards with a proxy, registered a new account with it, and proceeded to post in an entirely different typing style with his superior acting skills. In this manner he would manage to keep his primary and secondary accounts active on the forums for extended periods before he was discovered.
He also had a habit of creating an unstoppable wave of members with the same name, such as Nintendogs, due to a board error that Retriever II fixed shortly.
Sadly, Mugen was eventually banned indefinately for the Phisherman Fiasco. He is likely to manage a return.