Jock began his professional career at British comics magazine 2000 AD, on series including Judge Dredd and Lenny Zero, the latter with writer Andy Diggle.

[9] Following his run on Green Arrow he got more work on main DC universe titles, in particular two storylines on Detective Comics, the first featuring Batwoman and the second Batman.

With Guinness officials on hand to monitor their progress, writer Mark Millar began work at 9am scripting a 20-page black and white Superior comic book, with Jock and the other artists appearing on stage throughout the day to work on the pencils, inks, and lettering, including Dave Gibbons, Frank Quitely, John Romita Jr., Adi Granov,[11] Doug Braithwaite, Ian Churchill, Olivier Coipel, Duncan Fegredo, Simon Furman, David Lafuente, John McCrea, Sean Phillips and Liam Sharp,[12] who all drew a panel each, with regular Superior artist Leinil Yu creating the book's front cover.

The book was completed in 11 hours, 19 minutes, and 38 seconds, and was published through Icon on 23 November 2011, with all royalties being donated to Yorkhill Children's Foundation.

[11] Jock has contributed concept paintings and key art to a number of film productions and promotional campaigns, including Hancock, Battleship, Children of Men, Dredd, Batman Begins and X-Men: Days of Future Past.