From another era, it seems like. Thanks, Cartoon Title Art.
(Actually, Pen & crew wrapped up production on that first short in the spring of 2006. Nicktoons Network first aired the short in January 2007.)
Adventure Time - pilot (2008)
directed by Larry Leichliter, Hugo Morales, and Pendleton Ward
title art designed by Pendleton Ward, painted by Paul Linsley
Memories that make my head hurt.