A specific type of Berserk Button, this character is extremely defensive about their hair and will quickly become angry if it is messed up or damaged in some way. Often used to indicate the character is at least somewhat vain as hair is often seen as similar to a peacock's tail—a display—and so it is a very easy symbol for vanity in general. Often played for comedy, expect these characters to have very outlandish styles.
If it is Played for Drama, expect abuse and/or assault to be a major element in their backstory, possibly including being dragged By the Hair. Defensiveness over touching the hair can also come of Hair as Cultural Identity, where the person's hair and the way it's grown, groomed, styled, decorated and otherwise cared-for is a highly important part of the bearer's traditional cultures, and touching or playing with it without consent (let alone abusing it) can not only be extremely rude and insensitive, but actually count as a hate crime in some cases.
Compare Not in the Face!.