David Hellman is an artist living in San Francisco. Besides creating the graphics for Braid, he was on the selection committee and helped run the Experimental Gameplay Workshop at GDC in 2008.
Prior to game industry involvement, he drew an online comic called A Lesson Is Learned But The Damage Is Irreversible. Prior to that, he was a moss-covered elm. His portfolio and blog can be found here.
Features by David Hellman:
The Art Of Braid: Creating A Visual Identity For An Unusual Game [08.05.08]