It sees that One Punch Man sketch wasn’t a single sketch. Another sketch has been posted and it seems that monster wasn’t such a big deal. You can see it below along with the one from before. We also see someone else from another series appear.
Article:https://comicbook.com/anime/2019/01/02/one-punch-man-new-year-2019-sketch-manga-anime/
As always thank you for reading.