THERE'S NOT MUCH TO KNOW, he's a skeleton who is no longer a skeleton and he has brain problems and a mean nihilistic streak. There's some stuff about jokes in there too.

Shameless eavesdropping you say? Sans makes it his business to know just about everything there is to know about everyone, though once he has it he does very little with that info. He's just kind of a hoarder. A secret hoarder.

I'm very excited to bounce them against each other!