MuHAhaZ is the internet standard for an evil laugh. There is no rule as to how many times "HAha" can apply just that it must end in a 'silent Z' that must be preceded by a lowercase 'ha'.
Joe types, "I want to find your pink jellybean, MuHAhaHAhaHAhaZ!!" or "Your tongue is not likely to be long enough for that Joe, ... MuHAhaZ!!"
by [br0ken] June 25, 2011