R. Crumb was still a teenager when he created the character Fritz the Cat for self-published comics magazines he made with his older brother Charles. The character first appeared to a wider public in Harvey Kurtzman's humor magazine "Help!" in 1965. The strips place anthropomorphic characters—normally associated with children's comics—in stories with drugs, sex, and other adult-oriented content. Crumb left his wife in 1967 and moved to San Francisco, where he took part in the counterculture and indulged in drugs such as LSD. He had countercultural strips published in underground periodicals and in 1968 published the first issue of "Zap Comix". Crumb's cartoons became progressively more transgressive, sexually explicit, and violent, and Crumb became the center of the burgeoning underground comix movement. Fritz became one of Crumb's best-known creations, particularly outside the counterculture.