In order of publication, the first Killer Shark (1952) was a pirate who controlled an organization of pilots and sailors who flew fish-shaped vehicles. During Quality Comics' run, he was the most recurring villain of the Blackhawks.
After DC took over Quality and its titles, Killer Shark (1957) showed up again. He took a liking to Lady Blackhawk (Zinda Blake), and with the help of narcotics, he made her his Queen Killer Shark. After Lady Blackhawk was transported to the present in Zero Hour, the pirate's grandson also adopted the name Killer Shark (2008), and with his grandfather's poisons, made Zinda Queen Killer Shark again. He was apprehended and is still in custody; he is the only Killer Shark currently alive.A wholly unrelated Killer Shark (1984) was the German general Haifisch. During World War II, he was administered a super serum, granting him superhuman strength and longevity. He survived the war, but was killed by Zinda Blake.