“And that’s Smith of Hufflepuff with the Quaffle,” said a dreamy voice, echoing over the grounds.  “He did the commentary last time, of course, and Ginny Weasley flew into him, I think probably on purpose, it looked like it.  Smith was being quite rude about Gryffindor, I expect he regrets that now he’s playing them — oh, look, he’s lost the Quaffle, Ginny took it from him, I do like her, she’s very nice. . . .”
Harry stared down at the commentator’s podium.  Surely nobody in their right mind would have let Luna Lovegood commentate?  But even from above there was no mistaking that long, dirty-blonde hair, nor the necklace of butterbeer corks. . . . Beside Luna, Professor McGonagall was looking slightly uncomfortable, as though she was indeed having second thoughts about this appointment.

“. . . but now that big Hufflepuff player’s got the Quaffle from her, I can’t remember his name, it’s something like Bibble — no, Buggins —”
“It’s Cadwallader!” said Professor McGonagall loudly from beside Luna.  The crowd laughed.

Harry Potter and the Half-Blood Prince – J.K. Rowling