矛头蝮长达8英呎。矛头蝮的背上环斑可融入雨林的落叶地表，帮助牠们长时间等候猎物。矛头蝮受干扰时会像响尾蛇一样举起尾巴发声警告入侵者(尾部无响环)矛头蝮会受人类住宅区的老鼠吸引而来到人类的住所，在南美洲有高达八成的蛇类咬伤案例元凶都是矛头蝮。矛头蝮的毒液会瓦解伤口周遭的组织，毒液还会随着血液蔓延破坏血液组织，最后导致心脏及肾脏衰竭。

Bothrops atrox — also known as the common lancehead, fer-de-lance, and barba amarilla — is a species of pit viper found in the tropical lowlands of northern South America east of the Andes. No subspecies are currently recognized.