ok ok ok so Night in the Woods,
if you get Mae’s dad to move the boxes blocking the crawlspace there’s a safe, and if you keep checking up on the bookshelf everyday eventually you’ll find a note that has the safe combination and there’s a tooth in it
and in the newspaper clippings it talks about this secret historical society that killed some dude and then took his teeth as a right of passage type thing.
keep in mind that when a member of the society passes, the tooth goes to whatever new member would replace them. so why was Mae’s granddad’s tooth locked away in a safe?