Iconic Skeleton Grin

Don't be, Sans, Barrel came long before you so he's not trying to be like you XD

Here's a headcanon for you guys (since I always imagined Barrel to grow up to be a skeleton anyway)
What if Sans is actually adult-Barrel?
... I know it's very far-fetched, but it's just a headcanon, they can be as far-fetched as we want XD

The Nightmare Before Christmas belongs to Tim Burton
Undertale belongs to Toby Fox