The 1937-D Three-Legged Buffalo Nickel was a Denver Mint mistake. The buffalo's front leg was removed due to over-polishing the coin dies, leaving three legs.
Though 17 million Buffalo Nickels were coined in Denver in 1937, just 10,000 Three-Legged ones remain.
The vintage Buffalo Nickel, designed by James Earle Fraser, is popular. The reverse depicts a buffalo, perhaps modelled after “Black Diamond,” a Central Park Zoo buffalo, and the obverse a composite depiction of three Native American chiefs. s.
Collectors have sought the Three-Legged Buffalo Nickel since 1937. During a hobby boom after WWII, its popularity skyrocketed.
Many counterfeiters have tried to copy the 1937-D Three-Legged Buffalo Nickel due to its high value. To replicate the inaccuracy, some have modified Buffalo Nickels by removing the front leg.