The blue tree monitor (Varanus macraei) is a striking species of lizard native to the island of Batanta in Indonesia. It is known for its vivid blue coloration, which sets it apart from other tree-dwelling monitors. Blue tree monitors typically grow up to 3 feet in length, with long tails that help them balance while climbing. Their agile, slender bodies and sharp claws make them excellent climbers, well-adapted to their arboreal habitat in tropical forests.

These lizards are carnivorous, feeding on insects, small mammals, birds, and occasionally eggs. They are known for their intelligence and are highly active, using their strong sense of smell and keen vision to hunt.