"i wouldn't be so sure of that, pal."

In the next blink of an eyesocket he's normal again, unassuming as ever.

It's not like he wouldn't mind having to kick this guy around a bit - it's just that it sounds like an awful lot of work. And look at this, it's a party. Parties are for kicking back and not fighting with one another, unless your name happens to be Undyne.

Sans is reasonable. Even better, Sans is too lazy not to be.

"let's try this again. you guessed my name. what's yours?"