He was also a member of Heaven, The Headhunters, Illustrated Men, Doomfoxx, Pete Wells' Heart Attack, and the Ted Mulry Gang.

He was the fifth member of Rose Tattoo to die of cancer, preceded by Dallas Royall (1991), Peter Wells (2006), Ian Rilen (2006), and Lobby Loyde (2007).

Lake and Vandersluys were substituted by former Buster Brown members Angry Anderson on vocals and Dallas "Digger" Royall on drums respectively.

[2][5] When Rilen left the group Cocks switched to bass guitar then Chris Turner (ex-Buffalo) was brought and, in turn, was replaced by Geordie Leach (ex-Buster Brown).

[2] In 1980 Cocks was also a founding member of The Headhunters – an ad hoc collection of R&B musicians – initially with Todd Hunter on bass guitar and his brother Marc on vocals (both from Dragon); John Watson on drums and Kevin Borich on lead guitar (both Kevin Borich Express).

[8] In late 1981, Rose Tattoo, with Cocks, returned to Australia from a tour of Europe and began work on their third album, Scarred for Life.

In May 1982 Cocks replaced John Haese on guitar and the group toured the United States' West Coast supporting Mötley Crüe and Dio.

In 2003, Cocks rejoined Rose Tattoo to write tracks with Anderson which were recorded for a future album, Blood Brothers.

Sessions were disrupted by Wells' illness and eventual death of prostate cancer on 27 March 2006, four years after his initial diagnosis.

[18] In April 2009, Cocks was diagnosed with liver cancer, manager Steve White stated, "Mick ... is now under the advice of the very best doctors in Sydney.

[19] In July, a benefit concert with Rose Tattoo, Jimmy Barnes, You Am I, Ian Moss and The Screaming Jets played at the Enmore Theatre in Sydney to raise money for Cocks.