Bothrops moojeni, commonly known in English as the Brazilian lancehead, is a highly venomous species of snake in the family Viperidae.

[1][2] The specific name, moojeni, is in honor of Brazilian zoologist João Moojen de Oliveira (1904–1985).

[4] Grows on average 160 cm, with a maximum of 230 cm already reported, has a tan, gray-brown or olive-gray color, with fourteen to twenty-one trapezoidal side marks that are dark gray or completely black, 23 to 29 lines of dorsal scale of the average body, with the belly usually white or cream with dark gray spots scattered, while juveniles have a white tail.

[9] In South America common names for B. moojeni include caiçaca, caissaca, caiçara, jacuruçu, and jararacão.

[12][13] Moojenactivase, a procoagulant metalloproteinase is capable to induce DIC with a high toxic potency, characterized by prolongation of Prothrombin and activated partial thromboplastin time, consumption of fibrinogen and the plasma coagulation factors like Factor X and II, and thrombocytopenia, it also caused Intravascular hemolysis.