A skull with a lightning bolt from the Steal Your Face record is the symbol most associated with the Grateful Dead. The design was by Owsley Stanley, who besides being a great graphic designer was also one of the earliest mass cooker of LSD. His total production is estimated at around half a kilogram of LSD, or roughly 5 million 100-microgram "hits" of normal potency, although accounts vary widely. Here's some classic Nazi SS imagery on one of their pennants, lightning bolts & skull. What must be noted here, is that the prevalence & impact of Nazi imagery in American pop culture (which we document) was much different up until about 1980 for some reason. I'm still trying to figure out what changed, but kids used to be able to buy plastic Nazi helmets in the backs of comics, replica Nazi medals complete with the big scary swastika in the Johnson Smith catalog & read Nazi war comics up until about 1980, so the Grateful Dead referencing Nazi stuff back in the late 60s/early 70s was going to be more associated with Bikers, who were just seen an the filthy degenerates they were, instead of world domination plotting & almost successful German Nazis.
