Zac Efron's trademark shaggy hairdo has undergone a frightening transformation, but there's a perfectly good reason for this hair-raising look. Zac is currently shooting the comedy "Seventeen" in Santa Monica which hopes to bring back the whole genre of "grown-up turns into a kid" flicks that were so popular in the mid-to-late 80s. In the film, Zac plays a teenaged Matthew Perry, who rocked a similar 'do during the first season of "Friends", if I recall correctly. Zac's character is a basketball player, and he does look quite athletic in his tight tee and track pants. I do hope that hair is also for his on-screen character, Zac doesn't look right with a "hair helmet!"