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A MUD player who eats, sleeps, and breathes MUD. Mudheads have been known to fail their degrees, drop out, etc. with the consolation, however, that they made wizard level. When encountered in person, on a MUD or in a chat system, all a mudhead will talk about is three topics: the tactic, character, or wizard that is supposedly always unfairly stopping him/her from becoming a wizard or beating a favourite MUD; why the specific game he/she has experience with is so much better than any other; and the MUD he or she is writing or going to write because his/her design ideas are so much better than in any existing MUD. See also wannabee.
To the anthropologically literate, this term may recall the Zuni/Hopi legend of the mudheads or "koyemshi", mythical half-formed children of an unnatural union. Figures representing them act as clowns in Zuni sacred ceremonies.