Spoiler: I REALLY DON'T KNOW WHAT TO PUT HERE BUT I CAN TELL YOU IT HAS SOMETHING TO DO WITH UNDERTALE. AM I LIKE THE FIRST ONE TO USE THIS SPOILER THING? I DON'T REALLY KNOW. HOWEVER I WILL DISCUSS A VERY SERIOUS TOPIC ABOUT UNDERTALE. I ACTUALLY THINK THIS TITLE IS LONGER THAN THE STUFF I'M PUTTING IN IT. OK I'M ABOUT TO END MY TITLE. RIGHT... ABOUT... NOW!!! ^_^ LETS TALK ABOUT SANS You see this guy? He's a skeleton. BUT MAYBE HE'S NOT A SKELETON First of all, HE'S TOO FAT FOR A SKELETON. Being "big boned" isn't a thing. The bones stay the same size, it's the skin and fat that makes you look "fat." So, if Sans is a skeleton, he wouldn't have skin. Meaning he wouldn't be fat. Second, Sans never takes off his jacket. Meaning he could be hiding something. Sans' sprite shows some white in between his jacket. It looks like a spine and a few ribs. Nothing else. No boney structure is shown on Sans except for his head. Speaking of his head... Third, HIS HEAD LOOKS LIKE A MASK. He is always smiling. Plus, his "eye sockets" are empty except for two dots in the middle. Implying that there are no eyes in his skull except for the eyes of the person inside. Fourth, HE BLEEDS. HOW CAN A SKELETON BLEED. And it can't be the massive amounts of ketchup he drinks since, as a skeleton, it would fall through him. tl;dr SANS IS NOT A SKELETON, BUT A HUMAN IN DISGUISE I THINK THIS SPOILER TITLE WAS TOO LONG :/
Congrats you watched theory videos. And read some stuff. Gee wilikers. And also, if he IS human, how and why did he stuck a giant skull on his head.
Continuing. How exactly does a mask sweat? I know, it may be to express the seriousness, like the vid said, but still. Also, Winking? Now thats outta the question for a mask. And the final nail in the theory: I spy with my little eye, something looking like... A spine! And going straight into a skull no less! Awaiting rebuttal if you have one. Ps: Get Dunked On
The human inside is sweating because he is attacking Frisk. He's under a LOT of stress. Not only that, a mask doesn't just hold in sweat, it gets out one way or another. Also, Sans has a BREATHING animation while papyrus does not. Winking? Winking you say. A skull can't wink either. So it'd make sense that the human found a way to make a mask wink. A spine!!! Yeah! ALSO PART OF THE DISGUISE. Spoiler: And guess what I found on Pinterest
Sans breathing is due to being lazy, he isn't used to situation like that, it's like a fat person running. And about the sweat, Papyrus sweats too. Sans sleeps maybe cause he chooses to, like Amethyst in Steven Universe, and monsters do need to eat, i mean, why would Papyrus cook spaghetti if not for eating? Dunno about that Gaster splitting stuff, but I can tell you one thing, its still unconfirmed if that "mysteryman" is Gaster. You're fun to exchange arguments/theorise with, maybe we can think up something new or find a new clue if we keep this up.
Skeletons don't breathe... so how is he breathing. Also, yeah, we should make some theories later on!