Author Avatar: Based on a teenage Pat McHale, with his costume being inspired by a hypothetical "rock star alter-ego" he imagined for himself back then but never implemented.
It's implied part of this is Wirt projecting resentment for his stepfather onto Greg ( said stepfather's biological son). Aloof Big Brother: Starts easily irritated with Greg and doesn't really care much when he wanders off.And if he got the nerve to actually speak to her like Greg insisted, he would've learned that Sara hadn't listened to it yet since she doesn't have a cassette player to play it. All for Nothing: His attempts to run away from Sara after she gets his mixtape and the fear he had of her listening to his poetry ends up with him and his brother drowning in a lake and entering the Unknown, where Greg nearly became an Edelwood Tree.The hat he finds with it implies it's a Union soldier's cape (real or costume). All-Encompassing Mantle: Wirt's cape, an appropriate visual symbol of his insecurity.A poet who has a way with words, but is awkward around people. The older of the two brothers, a teenager who is more responsible than his younger brother, but has a habit of getting caught up in himself.