Uracoan rattlesnakes are nocturnal solitary snakes that give birth to up to 10 young between 120 and 160 days after mating. Their diet is primarily made up of small lizards, but expansion of agricultural activities has introduced small rodents into its diet.

Their life span is between 15 to 20 years and they are a shade of pale olive green, rust brown, or gray with numerous white-tipped scales scattered on their head and body.

Crotalus vegrandis is limited to a specific ecological niche of small relictual forests and surrounding wet savanna among the central highland plateaus of plateaus in Monagas and Anzoátegui States in Venezuela.

Their venom has neurotoxic, hemotoxic and myotoxic components, which can induce paralysis, severe hemorrhaging and muscle failure.