If it weren't for his thinking of this as tug-of-war with one of the dogs back home, Papyrus would have lost his grip with the shaking. As is, he barely keeps up with the movement, each whiplash jostling his arms even as it loosens the maybe-Sans' teeth.

"What are you doing??" Papyrus scolds reflexively, even as the merrow's shape flickers from time to time with pointy reptile touches. "Come with us or let go! You're going to hurt your neck doing that."

Normally that wouldn't be too bad - normally healing magic isn't so unusual. A fair few monsters can muster a tiny bit of it, enough to help recovery with encouraging words, and Papyrus himself can do a bit more than that. Being as much a gentleman of a fighter as he considers himself, he makes sure to heal up his opponents, even when they're a human and his hopes for popularity and fame and promotion rest on capturing them. But like a lot of things, that doesn't seem to be working right in this dream.