Since 1986, Brett Koth has collaborated with Jim Davis on the writing and art for the Garfield comic strip, along with licensing for the cat, which has included design and art for projects as diverse as a petting zoo, a planetarium show, a Rose Parade float and elementary-level English reading textbooks for schools in China. He also worked on many of the CBS "Garfield" television specials, and on the first season of the "Garfield and Friends" Saturday AM series. Additionally, Koth has contributed writing and art for the NEA Bugs Bunny strip. And he still writes for the cat.

Diamond Lil fell out of Koth's head in late 2008, a mash-up of many older ladies he's known, and he's eager and excited to turn her loose on an unsuspecting public.