Casey A. Royer (born October 8, 1958),[citation needed] is an American musician and an early pioneer of the hardcore punk rock genre in Orange County.

Southern California's surf scene and Royer's suburban upbringing would later influence much of the punk rocker's lyrical and fast-paced musical style.

[citation needed] Royer attended Troy High School, and began playing music with friends in the neighborhoods of Fullerton and Placentia, California.

[2] Royer began playing the drums professionally in 1978 at the age of 20, as a formative member of Social Distortion with Mike Ness.

In addition to forming and naming the band, Royer wrote "Mommy's Little Monster" and composed the group's early lyrics with occasional help from original lead vocalist Tom Corvin.

[5] The song has been featured in films and video games, such as Tony Hawk's Pro Skater 3 (2001), Grand Theft Auto V (2013) and Call of Duty: Black Ops Cold War (2020), SLC Punk, The Carrie Diaries, and more.

Director Penelope Spheeris recruited street youths and punk-rock musicians to represent each role rather than hiring actors.

Due to creative differences, Adolescents founders Tony, Frank and Steve kicked out Blue Album line-up members Casey Royer and Rikk Agnew.

Casey wrote a popular song on the Blue album titled "Amoeba", now considered a punk rock anthem.

Steve, Tony, Frank, and Rikk shared songwriting credits for the rest of the Blue Album, creating the iconic Orange County sound recognized worldwide.