Scout and Jem’s friend Dill has a cowlick in the middle of his forehead.
A cowlick is a bit of hair that stands out from the rest of the hair, usually on a person’s forehead. When Scout and Jem first meet Charles Baker Harris, also known as Dill, he is rather strange looking.
Dill was a curiosity. He wore blue linen shorts that buttoned to his shirt, his hair was snow white and stuck to his head like duckfluff; he was a year my senior but I towered over him. (ch 1)
Dill is also described as constantly pulling at the cowlick in the center of his forehead. When Scout and Jem play with him, he is an entertaining change from their time of only having each other.
Dill provides a meaningful extension of Scout and Jem’s activities, and becomes part of the family as he shares in the Finch adventures.