I’ll make Goyle do lines, it’ll kill him, he hates writing,” said Ron happily. He lowered his voice to Goyle’s low grunt and, screwing up his face in a look of pained concentration, mimed writing in midair. “I... must... not... look... like... a... baboon’s... backside.

~ J.k. Rowling

J.k. Rowling Baboon Detention Gregory Goyle Humor Punishment Ron Weasley

Ooh, you look much tastier than Crabbe and Goyle, Harry said Hermione, before catching sight of Ron's raised eyebrows, blushing slightly and saying oh you know what I mean - Goyle's Potion looked like bogies.

~ J.k. Rowling

J.k. Rowling Gregory Goyle Hermione Granger Humor Polyjuice Potion Ron Weasley Taste