Crotalus unicolor, or the Aruba Island Rattlesnake, is a venomous pit viper species endemic to the Caribbean island of Aruba, off the coast of Venezuela. It is sometimes still classified as a subspecies of Crotalus durissus.

Yes, Aruba is home to one significant venomous resident: the Aruba Island Rattlesnake (known locally as the Cascabel). This snake is endemic to the island and is one of the rarest rattlesnakes in the world; it is primarily found in the rugged, arid terrain of Arikok National Park. While venomous, it is generally reclusive and avoids human contact. In the water, travelers should be aware of Portuguese Man o' War and various species of jellyfish that can wash up on the shores, especially after storms; their stings can be very painful but are rarely fatal. On land, you might also encounter the Baker’s Scorpion, which can deliver a sting similar to a bee's. Regarding flora, the Manchineel tree is found on some beaches; its sap and fruit are highly toxic and can cause severe blistering on contact. It is a good rule of thumb in 2026 to avoid touching unfamiliar wildlife or standing under trees marked with red warning paint.