His knee-jerk reaction to the prodding? To kill whoever (or whatever) touched him. He moves more quickly than the eye can follow - one moment, he's turned away from Howl, sleeping; the next, he's behind the wizard and he's got the chain connecting his cuffs underneath the man's chin and pulling back, using the chain as a makeshift garrote.

That is, until he recognizes exactly who had poked him - then he relaxes and pulls away, moving back to his place where he had been sitting beforehand, glancing sidelong at the other. He's not going to apologize for that, but he will warn Howl against doing so in the future.

"It is generally not a good idea to interrupt my sleep, wizard." Oh well, better late than never.