from "The Phoenix Lament"

page 625
(McGonagall) "...Hagrid, please tell the Heads of Houses -- Slughorn can represent Slytherin -- that I want to see them in my office forthwith. I would like you to join us too.

page 628
"Hagrid, you haven't said anything," said Professor McGonagall....
Hagrid...croaked, "I dunno, Professor... that's fer the Heads of House an' the headmistress ter decide..."
"Professor Dumbledore always valued your views," said Professor McGonagall kindly, "and so do I."