"I know you aren't Slytherin, but I really can't be having with all this self-depreciation just because you also wish to value others," he says severely. "It's simply not on."
"'Serpent,' as a word," he explains, "has connotations of subtlety, of wisdom, of guile-used-to-purpose, can also be used to describe a dragon. To be a snake necessitates no other trait but cunning." He raises an eyebrow half-rueful, half cynical at life. "And that's all?"
"Most likely not, if you take care to be polite. He's heard me mention your presence, so he'll know you approach him through a mutual connection; that generally helps." He pauses reflectively, and adds, "Of course, I have no intention of volunteering involvement in his and Miss Weasley's rather... exotic enterprise."