New York artist Keith Haring, known for his joyful cartoons and vivid graffiti, was honored with his own Google Doodle on Friday on what would have been his 54th birthday. Haring died in 1990 of AIDS-related illnesses. An Andy Warhol mentee, Haring was an unabashed populist, first making a name for himself with chalk works he created in New York subways. Over the course of his too-short career, Haring became known for his whimsical touch and murals dealing with social issues. Before dying at the age of 31, Haring created a foundation that bears his name to draw awareness to the danger of AIDS, and became an advocate for safe sex.