Urban Legend: a story that appears mysteriously and spreads spontaneously in various forms and is usually false.
The “Blue Star Acid” story warned of a form of LSD soaked tattoo that was being sold to school children. The designs on the sheets were said to be the size of a pencil eraser and included images of blue stars, butterflies, Superman, Mickey Mouse, Bart Simpson, etc. Symptoms of exposure included vomiting, extreme laughter, and mood changes. Warning fliers were distributed in the U.S. on the letterheads of schools, companies, churches, and day-care centers. Police and journalists have consistently proved this information wrong though it is possible that this urban legend originated from an actual police bulletin that warned that children might mistake LSD tabs for tattoos.
Source: Encyclopedia of Urban Legends