The Fer-de-Lance pit viper is considered the "ultimate pit viper" due to its large size, fangs, and venom yield. Its fearsome reputation also comes from having the most snakebites within its range due to being highly defensive and unpredictable when disturbed. However, like other venomous snakes, the Fer-de-Lance avoids confrontation with humans whenever possible.

Its habitat extends from northeast Mexico and Central America into South America, living in low elevations to the north and up to 2600 meters in the Andes to the south. The Fer-de-Lance can grow up to 8.2 feet long and is among the largest of pit vipers. Its name "Fer-de-Lance" is French Creole, translating to "iron of the lance" or "iron spear point". 

The venomous bite of the Fer-de-Lance has been suggested to have been a factor in the choice of certain Mayan settlements, such as Nim Li Punit, Belize where the thick jungle inhabited by these snakes was used as a defensive boundary.