you hear footsteps behind you, it was killer sans but you didnt know that, he mutters to himself something about a knife in the hand trick and then he teleports infrount of you

hey bud, dont you know how you greet a new friend?

something is definetly off... you swear you can see a glint of light from a reflection from... what you think is a knife... in his sleeve.. he puts that hand out for a handshake.