Watch the vid and you shall understand everything

[There should be a GIF or video here. Update the app now to see it.]

Read after watching this:

DO YOU KNOW WHAT IT MEANS?!

Edit: if there's no video just find me in UT amino if you have. My name is "RandomGamerLEX" and the name of the post is "ATTENTION ALL UNDERTALE FANS"

If you don't have, just search in YouTube.
"Undertale: trailer (Live action)" it has greater dog on it.

If you've watched it, put in comments. Thanks and sorry!