“Hello' said a vague and dreamy voice from behind them. Harry looked up: Luna Lovegood had drifted over from the Ravenclaw table. Many people were staring at her and few people openly laughing and pointing; she had managed to procure a hat shaped like a life-size lion's head, which was perched precariously on her head.
'I'm supporting Gryffindor' said Luna, pointing unnecessarily at her hat. "Look what it does...'
She reached up and tapped the hat with her wand. It opened its mouth wide and gave an extremely realistic roar that made everyone in the vicinity jump.
'It's good, isn't it?' said Luna happily. 'I wanted to have it chewing up a serpent to represent Slytherin, you know, but there wasn't time. Anyway...good luck, Ronald!”