That’s in the book. Grimmauld Place has the preserved heads of all the Black family elves hanging by the door. During book 7 when Harry and gang are hiding there, they put Santa hats and beards on the heads for Christmas.

These are supposed to be the good guys.

Shaun has a takedown of the entire series on his channel, and this is one of my favorite parts:

so our heroes decide to decorate their decapitated slave heads with little Christmas hats…

now I’m gonna need to hit pause here, next to the Christmas slave heads, and ask: what is happening right now… why are the Harry Potter books like this

not my absolute favorite quote either. long video but definitely recommend; even Shaun’s extremely dry delivery breaks at a couple points: https://youtu.be/-1iaJWSwUZs