Beware, some spoiler stuff!
Dr Alphys and a certain little ghost, back when she wasn’t the royal scientist and  he wasn’t a famous tv star. They’re both coming up with some ideas for his new body.

Also

(By the way mettaton’s ghost form is heavily inspired by a pic I saw on 8tracks but I have no idea who drew it, if you know who I’m talking about pls send me a message!)