||Chamaeleo jacksonii (common names Jackson's Chameleon or Three-horned Chameleon) is an African chameleon belonging to the chameleon family (Chamaeleonidae).
There are three subspecies:
* Chamaeleo jacksonii jacksonii Boulanger 1896 : Jackson's Chameleon
* Chamaeleo jacksonii merumontanus Rand 1958 : Dwarf Jackson's Chameleon
* Chamaeleo jacksonii xantholophus Eason, Ferguson & Hebrard 1988 : Yellow-crested Jackson's Chameleon
They are native to the humid, cooler regions of Kenya and Tanzania, East Africa, found in great numbers at altitudes over 3,000 m. The subspecies merumontanus can only be found on Mt. Meru and the Arusha districts of Tanzania. The subspecies xantholophus was introduced to Hawaii in the 1970's and has since established a large feral population. This population was the primary source of Jackson's Chameleons for the exotic pet trade. However, the exportation of these animals (and many others) from Hawaii for the pet trade has been made illegal to prevent opportunists from willfully establishing further feral animal populations in order to capture and sell them.
These are small to medium sized chameleons. Their adult size is 12 inches (30 cm) in total length. They have a saw-tooth shaped dorsal ridge. There is no gullar crest. They attain maturity after five months. The lifespan is variable, with males generally living longer than females.