The Dragon Card mailed on April 28th 1970, seemed to depict Don Quixote and Sancho Panza, two characters created by author Miguel de Cervantes Saavedra in 1605 and 1615, and the subtle reference in the accompanying text to Melville Eats Blubber, pointed towards Herman Melville, an American novelist, famous for his penning of Moby Dick in 1851.
The greetings card and text seemed to reveal little. The Zodiac Killer placed the line "I hope you enjoy yourselves when I have my blast" on the card, in reference to his concealed bomb. Then in the attached letter made reference to his Zodiac buttons, that he wanted people to wear. But it is conceivable there was a lot more.
The Zodiac Killer first mentioned the use of bombs in the 'Bus Bomb Letter' on November 9th 1969. But what was his trigger?
In 1969 eight bombings wreaked havoc in New York City, targeting government and commercial buildings. The perpetrator was Sam Melville, justifying his reasons for the carnage on the United States involvement in the Vietnam War and US imperialism.
The bombings, all in 1969, occurred on July 27th, August 20th, September 19th, October 7th and culminated with a succession of four explosions in close proximity of one another, on November 11th and 12th. Sam Melville was born Samuel Joseph Grossman in 1934, but changed his name to Melville, because of his admiration for Herman Melville's novel Moby Dick.
The Dragon Card was mailed on April 28th 1970 and the Button Letter soon followed on June 26th 1970, both continuing the theme of bombing in the text. The Zodiac Killer also gave us a fourth code and Phillips 66 Route map, stating that together they would reveal the location of a 'hidden' bomb.
The Dragon Card text referred to Herman Melville by association. In fact the text 'melvin eats bluber' is considered by many an irreverent slight towards Melvin Belli. The prominent lawyer was the recipient of a previous Zodiac letter on December 20th 1969, that included a second piece of Paul Stine's shirt, the taxi driver brutally gunned down in Presidio Heights on October 11th 1969.
But next to 'melvin eats bluber' on the Dragon Card, the Zodiac refers to 'black power'. Sam Melville teamed up with Jane Alpert and other members during their bombing campaign, eventually aligning themselves towards the Weather Underground, Black Panther Party and Black Power movement.
Was the Zodiac Killer influenced in his actions, reading about the New York bombings, determined to bring the fear it created into the heart of California and part influencing his style of writing within the Dragon Card itself.
Of course the Zodiac Killer never followed through on any of his explosive threats and his later correspondence appeared more of an attempt to maintain his share of the headlines. He knew very well that the authorities would have to consider his threats as real and seemed to delight in this fact.
Herman Melville not only wrote novels, but published poetry in his later life and was the author of many short stories. Surprisingly despite the worldwide recognition of Moby Dick today, it was not warmed to by the public at the time and effectively ended his career as a revered novelist.
In the short story The Piazza, Don Quixote was said to be 'the sagest sage that ever lived'.
His uncollected poems included Marquis de Grandvin at the Hostelry, The Wise Virgins to Madam Mirror, Gold in the Mountain and Naples in the Time of Bomba. The latter of which was finally published under this title by Raymond Weaver in 1924.
Ferdinand II of the Two Sicilies succeeded to the throne in 1830, initially popular, he later became a focus for rebellion and when Sicily declared its independence under Riggeru Settimu, his response was brutal, sending a naval flotilla to shell the uprisers for eight long hours, becoming synonymous with the nickname 'Bomba' or 'King Bomb'.
This features prominently in works by Melville, who refers to this period in his writings. See here.
The Zodiac Killer may have been well read, and it is his upbringing and influences that would have forever left imprints, that he deliberately or inadvertently incorporated into his own writing style, during much of his later correspondence.
Of course the suggestion, he took all of the above into account when designing his Dragon Card is highly unlikely and not the purpose, it merely expands on an otherwise bland correspondence and any influences that may have led to its inception.
Herman Melville, Moby Dick (1851).