Zack's only appearance during the short film
|Birth name||Zack Phineas Melto|
|Height||< 5' 8"|
|First appearance||Welcome to Hell short film|
Not much about him is revealed due to his short amount of screen time. However, it is known that he participates in a sport that could earn him the letterman jacket he wears, he has brown hair, and that his last name is Melto.
Wester says that he is a "typical, bulky jock" who "probably has a history of picking on Jonathan".
A colorist on the film, Hannah Melto, created a fanon personality for Zack. She says he's intuitive and "kinda dim and friendly like a dog [sic]". He has a crush on Jonathan Combs that makes him shy and awkward around the other boy.
- Zack's last name is a tribute to the aforementioned colorist.