Now that I have a proof-of-concept for monsters in a graveyard, which sprite should I use: ghosts or skeletons? Or both?

Both.

skeletons. hey how was your Christmas and newyear?

Good thanks :)

That's good to hear I hope you have a great week :)

I think skeletons. But maybe you could add a ghost who has a side quest (if you want to add any).