Kid Charlemagne

Kid Charlemagne was a San Francisco chemist known for producing very pure LSD without chemicals such as kerosene that were often used in LSD. In Spring, 1968, Kid Charlemagne provided some of his LSD to the band HPL just prior to their going on-stage for a concert at the Fillmore. George, the band's de facto leader, was under the influence of the LSD when a shoggoth attacked the Fillmore not long after.

Literary comment
Kid Charlemagne is likely a fictional analog of the historical Owsley Stanley (1935-2011), a San Francisco chemist known for producing very pure LSD in the 1960s. The Steely Dan song "Kid Charlemagne" is loosely based on Owsley. He was not called by the name "Kid Charlemagne" during his heyday, however.