Charlie Adlard is an artist and pencilled who started working for 2000 AD with the series Armitage. At this time his artwork was fully painted, but he has evolved over time to the point where his most recent work uses large blocks of black ink on the page to create bold shadow effects and thus makes his work very distinctive. Charlie also worked on series including Judge Dredd, Nikolai Dante, Rogue Trooper and most most notably Savage for 2000ad.
Most people will recognise him from his work on The Walking Dead. In 2004 he replaced the original artist Tony Moore and together with the writer Robert Kirkman, they have had one of the longest and most successful uninterrupted runs in modern comics.
Thanks to John Burdis for providing me with the sketch.