Would need to watch the old Universal Monsters films again but I believe it was the Book of the Dead (depending on which iteration; the mythology varied from film to film for some bizarre reason). So the mummy wasn’t looking for its mummy but its book. It should have gone into repo work with a library! Sadly, the Library of Alexandria is no more 🙁
Will test! Give me a bit! Got some other things to take care of 🙂
Edit:
Sorry, it was the Scroll of Thoth in the original. I think it was the Book in the version from Twenty years ago. In another one, it was a ring as I recall
https://en.wikipedia.org/wiki/The_Mummy_%281932_film%29
Too many!