The island of Caligo is home to a large number of endemic species. The plant and animal life developed in nearly complete isolation over about 70 million years. With the lack of human settlers to introduce a wider variety of species of plants and animals, the island still today remains detached from the rest of the world. While the types of animals may be similar to the ones found in locations nearby (like Florida and Cuba), there also exists numerous indigenous species to Caligo.

A unique aspect about Caligo is that all indigenous animals typically are very intelligent, more so than the animals found throughout the rest of the world. Animals native to the island are so smart in fact, that they are capable of learning human speech and can respond to human interaction.

Some marine mammals surrounding the island include Bottlenose Dolphins, Short-finned Pilot Whales, North Atlantic Right Whales, and West Indian Manatees.

Reptiles range from the American Alligator and Crocodile, to the Eastern Diamondback, Pgymy Rattlesnakes, Gopher Tortoises, Green and Leatherback Sea Turtles, and Eastern Indigo Snakes.

Amphibians are composed of a variety of frogs, toads, salamanders, and newts.

Mammals consist of a variety of creatures, including white-tailed and key deer, bobcats, rabbits, squirrels, wild pigs, mice and rats, bats, otters, foxes, wolves, cattle, and dark-furred feral cats unique to the island.

The bird life includes the eagles, osprey, pelicans, sea gulls, cranes, flamingos, and parrots, along with a variety of song birds.

There also is a large variation in insects and spiders, some being deadly and venomous.