What mythology has JK Rowling borrowed from other sources to construct the saga of Harry Potter?

So this older question from a few days back got me thinking about how a lot of the things in Harry Potter are basically mirroring popular myths from somewhere else.
Not saying, whatsoever, that it’s a bad thing, and as was pointed out that most fantasy literature does this anyways.
But now I’m all curious, are there any myths that you recognize in the series that originally come from something else?
(For example, the Gryffindor sword being found at the bottom of a pond, kinda like Excalibur comes from the bottom of a lake, or Voldemort almost being a lich? And I wouldn’t know if that counts anyway, since that is a mythical creature, rather than an event.)
I’m sure there’s more, what have you noticed?