Cho Chang’s best friend, who betrayed Dumbledore’s Army to Professor Umbridge in Order of the Phoenix. In her brief appearance in Half-Blood Prince, her face is still scarred by pimples spelling out the word “sneak,” the result of an enchantment Hermione placed on all the members of the D.A. Harry’s vindictive pleasure at seeing this shows his tendency to categorize people as good or evil, rather than trying to understand or forgive their actions.