Mungo MacDuff was one of MACUSA’s original twelve aurors (Pm).
MacDuff did not survive to old age (Pm).
The descendants of the original aurors enjoy a special place in American wizarding society (Pm).
Mungo = possibly related to a Welsh word for "kind" or "gentle" (source: Behind the Name).
MacDuff = most likely from the Shakespeare character Macduff, the good guy who defeats the tyrannical Macbeth.