Ron gasped. 
“The silver doe!” he said excitedly. “Was that you too?”
“What are you talking about?” said Aberforth. 
“Someone sent a doe Patronus to us!”
“Brains like that, you could be a Death Eater, son. Haven’t I just proved my Patronus is a goat?”
“Oh,” said Ron. “Yeah . . . well, I’m hungry!” he added defensively as his stomach gave an enormous rumble. 

Harry Potter and the Deathly Hallows – J.K. Rowling