The 1932 The Mummy had the name of Im-Ho-Tep, also known as Ardeth Bey. In the first mummy film, Boris Karloff was the character of the mummy in that film. There was a sequence mummy movies after this and Boris Karloff played the mummy a few more times.
mummy is a mummy because the egyptians called them like that because they took all there organs except the heart because they though the mummy spirit was in there or something similar. The English word mummy is derived from medieval Latin mumia, a borrowing from the Persian mum which means bitumen
Feedback loop, perhaps. The more a name get associated with something, the more people want to name their children with that name and the name will get associated with more things and so on. For example, kingly names become known as kingly names which causes more kings to want the name.