[Papyrus is too pleased with himself to do more than sigh as Sans slips his bad pun into the conversation.]

Of course! But then you should be on your way, I don't want you getting too proud of me and giving away the surprise! You see...

[He indicates the other end of the hall, where Sans had come in from.]

The enemy will enter through there, and be instantly accosted with both icy ground and the first two plates of my famous spaghetti! I believe that alone will be enough to entice them, and they'll realize we're far more friendly and pleasant to be around when we're alive. But worry not! As you can see, I planted spaghettis around here and there, so they have plenty of chances to reconsider before they reach me!

And in the meantime, they'll be stumbling on ice they hardly know how to navigate. It's perfect!