Zac Efron was a celebrity who starred in High School Musical. (PROSE: Head of State)
Rani Chandra had a poster of Zac Efron on her bedroom wall in 2009. Eve discovered her fondness for him when she read Rani's mind. They both agreed that he was "fit". (TV: The Mad Woman in the Attic)
Rachel Edwards said on her blog that Matt Nelson's entourage treated him like he was Zac Efron. (PROSE: Head of State)
When shown an image of her husband by the TARDIS, Natalie Morrison asked for Zac Efron instead, but was refused. (AUDIO: The Sorcerer of Albion)