Leach began his career at 2000AD, where the series he worked on included Dan Dare, Judge Dredd, and Gerry Finley-Day’s space opera The V.C.s. The obituary on the 2000AD website characterized his work this way:

While there was an intensity to his action sequences and stunning imagination in his designs, he also brought wonderful touches of whimsey – whether it was the harlequin-turned-hippie computer ‘Brother’ in The V.C.s, the nose-sucking plants of ‘Future Shocks: Bloomin’ Cold’, or Dredd’s striped socks in ‘Ten Years On’.

When the UK comic Warrior decided to revive the character Marvelman, editor Dez Skinn hired Moore to write it and Leach to draw it, although neither was his first choice. It was, however, a felicitous pairing: 2000AD described Marvelman as “a stunning deconstruction of the superhero genre that presaged Moore’s better-known work on Watchmen.” Leach’s influence lingered even after he left the comic, the obit noted:

Garry’s sharp-lined realism brought a languid, sinewy quality to Marvelman that befitted Moore’s intense psychological script. When Alan Davis took over as artist on the series, Garry inked his first few stories to allow him to settle into the strip and it was his style that remained the archetype for the rest of strip, even as it continued with Mark Buckingham.

(For more on the strange history of Marvelman/Miracleman, see “Confessions of a Comic Book Guy – Forward Into the Past”).

Leach left comics for advertising but returned in the 1990s as an inker for DC and Marvel, working on titles such as John McCrea’s Hitman and J. Michael Straczynski’s The Twelve.