In high school, she went by the name Missy and was a cheerleader, tennis player, and was on student council. As a junior and senior, McCarthy started dressing in black and "piercing her ears with safety pins." 

The actress told Anderson Cooper the transformation happened in one summer. She went from having a bob to dying her hair blue and black. McCarthy said much of it was more for show. 

"I was pretty lame, though, and much more of a goody-two-shoes than I looked," she told Rolling Stone. "Maybe occasionally I'd make out with some guy, but never anything further. I was usually the dork surrounded by a bunch of my gay friends."

"I acted like a maniac and looked like a really angry, violent punk," she added. "But I was always too chatty to be really angry."