The director of the Miami Serpentarium Laboratories, a facility near Punta Gorda, Florida, which produces snake venom for medical and research use. Haast extracted venom from venomous snakes from the time he was a boy. From 1947 until 1984, he operated the Miami Serpentarium, a tourist attraction south of Miami, Florida, where he extracted venom from snakes in front of paying customers.
Haast physically extracted venom from venomous snakes by holding them by the head and forcing them to strike a rubber membrane covering a vial. As a result of handling these snakes, Haast had been bitten 172 times.
Haast studied aviation mechanics and worked for Pan American World Airways. After the United States entered World War II, Haast served as a flight engineer on Pan Am airliners flying under contract to the United States Army Air Corps. These flights took him to South America, Africa and India, where he bought snakes to bring back to America, including his first cobra.
In 1946 Haast decided he had enough money saved to start his snake farm. He bought a plot of land facing U.S. 1, south of Miami, then sold his house and started construction on the Serpentarium. His wife Ann did not approve, and they eventually divorced. Haast retained custody of their son, Bill Jr. and continued to work as a mechanic for Pan Am while he built the Serpentarium. During this time Haast met and married his second wife, Clarita Matthews. The Serpentarium opened at the end of 1947, still not completed.
Haast extracted venom 70 to 100 times a day from some 60 species of venomous snakes, usually in front of an audience of paying customers. Soon after opening the Serpentarium Haast began experimenting with building up an acquired immunity to the venom of King, Indian and Capecobras by injecting himself with gradually increasing quantities of venom he had extracted from his snakes, a practice called mithridatism. In 1954 Haast was bitten by a common, or blue, krait. During the 1950s he was bitten by cobras about twenty times. Many times Haast donated his blood to be used in treating snake-bite victims when a suitable anti-venom was not available. More than twenty of those individuals recovered.
In 1949, he began supplying venom to a medical researcher at the University of Miami for experiments in the treatment of polio. The experiments gave encouraging results, but were still in preliminary clinical trials when the Salk polio vaccine was released in 1955.
3 marriages, 2 divorces.
Haast died on 15 June 2011 at age 100.

Link to Wikipedia biography