A low buzzing sigh. Not too happy with his kind? Then the doglike creature must not be his kind. What else he could be, Gaster doesn't know and can't ask.

He repeats his first gesture again, touching his chest and shaking his head resolutely.He's good, really, and it would be a long walk down to see the storm from below. Stop nagging, you're not his mother.

(Or a large goatman with the tendacy to carry lighter smaller people off over his shoulder. He finds himself smiling.)