Atelopus varius is endemic to Costa Rica and over the past few years, due to the spread of the fungus and climate change, the population of this species of frog has declined rapidly. At the moment, there is only one isolated population left. This species is now dangerously close to extinction.

The frog's colors (which vary between purple, black or yellow) warn predators to stay away as the frogs secrete a powerful toxic poison that is 100 times stronger than potassium cyanide. The only creature that poses a threat to Atelopus Mutable (besides humans) is a parasitic fly that lays its eggs on the frog's legs, allowing the larvae to burrow into the frog's skin. They then eat away the frog's internal organs, which ultimately kills it.