Adult Male Usambara Three-horned Chameleon (Trioceros deremensis), green color morph - The largest of the East Usambara chameleons, the three-horned chameleon can reach a total length of approximately 30cm. While this is large for a chameleon, it is not the largest in the world (the Malagasy giant chameleon (Fucifer oustaleti) grows up to 70cm) or the largest in Tanzania (the giant one-horned chameleon (Chamaeleo melleri) grows up to 55cm).