Can I like crawl out of a hole like an eldritch horror with spooky ambience leading up to it and then right when it looks like I'm going to like eat the
player I say, "Hi. Thank you for coming to my place. Just want you to know I believe in you! Merry christmas!!"
I can look like any monster and it could just be like a dark room with a scary music up til the reveal. Whatever is the easiest for you!