Lanza de hierro azul...

Blue Fer-de-Lance... Blue Pit Viper...
Nauyaca Azulada... Nauyaca (México; Nahuatl: nahui means four and yacatl means nose) "four noses" (two nostrils and two heat sensing pits)...

Here is Harry Greene speaking about an episode with a Terciopelo or Fer-de-Lance, Bothrops asper, a pitviper: "Regarding the gruesome snakebite sequelae for this species, Clodomiro Picado, Costa Rica's first academic biologist and a pioneering expert on snakebites, introduced a 1931 book this way:

Moments after being bitten, the man feels a live fire germinating in the wound, as if red-hot tongs contorted his flesh; that which was mortified enlarges to monstrosity, and lividness invades him. The unfortunate victim witnesses his body becoming a corpse piece by piece; a chill of death invades all his being, and soon bloody threads fall from his gums; and his eyes, without intending to, will also cry blood, until, beaten by suffering and anguish, he loses the sense of reality. If we then ask the unlucky man something, he may still see us through blurred eyes, but we get no response; and perhaps a final sweat of red pearls or a mouthful of blackish blood warns of impending death…

Other common names: Terciopelo, cuatronarices, nauyaca, labaria, mapanare, shushupe, fer-de-lance, jararaca, barba amarilla, yellow-jaw tommygoff, cantil, cantil boca dorada, cantil devanador, equis, equis negra, cascabelle, toboba rabo amarilla, pelo de gato, taya equis, jararacussu, surucucu, rabo de raton, kalakunaro, cascabel, jergon, jergon shushupe, bergi-owroekoekoe, boesi-owroekoekoe, morabana, oroekoekoe, caicaca, acuamboia, caissaca, bulla, machacu, taya, gewohnliche lanzenotter (plus many more slight local versions of these; more than 500 varieties)...