Lillard became the official voice of Shaggy Rogers after Casey Kasem retired from the role in 2009. He and Kasem collaborated for the first time on the series Scooby-Doo! Mystery Incorporated (2010), wherein Lillard portrayed Shaggy and Kasem portrayed Shaggy's father, Colton.
Was classmates with Paul Rudd at American Academy of Dramatic Arts.
Daughter Addison Grace was born June 13, 2002 in Los Angeles.