The savannah monitor (Varanus exanthematicus) is a medium-sized species of monitor lizard native to Africa. The species is known as Bosc's monitor in Europe, since French scientist Louis Bosc first described the species. It belongs to the subgenus Polydaedalus, along with the Nile, the ornate and other monitors.
The specific name exanthematicus is derived from the Greek word exanthem meaning an eruption or blister of the skin.French botanist and zoologist Louis Augustin Guillaume Bosc originally described this lizard as Lacerta exanthematica in reference to the large oval scales on the back of its neck.
Bosc's or savannah monitors are stoutly built, with relatively short limbs and toes, and skulls and dentition adapted to feed on hard-shelled prey. Maximum size is usually between 105 and 155 cm (3.5 to 5.0 ft) in length, although most specimens collected in the wild ranged from 60 to 76 cm (2 to 2.5 ft) with females being considerably smaller. The pattern of coloration of the skin varies according to the local habitat substrate. The body scales are large, usually less than 100 scales around midbody, a partly laterally compressed tail with a double dorsal ridge and nostrils equidistant from the eyes and the tip of the snout.
Information about the diet of savannah monitors in the wild has been recorded in Senegal and Ghana. It feeds almost exclusively on arthropods and molluscs. In Senegal, Iulus millipedes were the most common prey of adults; in Ghana, small crickets formed the bulk of the diet of animals less than two months old; orthopterans (especially Brachytrupes), scorpions and amphibians were the most common prey of animals six to seven months old .
The savannah monitor is a rather popular lizard pet in the trade. This is due to their docile disposition after much taming and they are one of the least-likely-to-bite monitors with proper handling. A savannah monitor that is not housed, fed and handled correctly can be a very aggressive lizard. 
Contrary to popular belief however, the savannah monitor fails to thrive in most captive situations. Thousands of savannah monitors are exported from the grasslands of Ghana, Africa annually for the exotic pet trade, typically farmed or collected from their natural environment. As a result, the species suffers widely from parasites, stress and injuries from conflicts with other savannah monitors during shipment.
Furthermore, the savannah monitor is considered to be a very misunderstood lizard when it comes to ideal husbandry. Proper care has yet to be established, but certain conditions are more adequate than others. The savannah monitor is at heavy risk for obesity, typically due to improper diet and lack of exercise. It is recommended to keep these animals very lean. Female savannah monitors often perish due to inability to lay eggs during ovulation cycles because of excess fat reserves putting extreme pressure on internal organs. Lastly, this species often succumbs to gout, dehydration and organ failure.
Due to the Savannah monitor failing to thrive in human care, it is extremely vital to the animal to provide the most up-to-date husbandry from the start.
It is strongly suggested to provide the savannah monitor - even as a young, small animal - an 8 foot by 4 foot by 4 foot enclosure. Glass aquariums and tanks are not recommended due to the inability to allow for proper thermoregulation, humidity and substrate depth. Deep, sandy soil should always be provided, the depth meeting or exceeding 24 inches. Correct heat and humidity is vital for the savannah monitor's survival in captivity. Temperature gradients of 140° degrees or hotter must be provided, in addition to 60%+ humidity. Substrate should be kept moist enough to hold burrows and humidity, but not soaked.
Diet of the savannah monitor in captivity is controversial. Whole prey rodents such as rats and mice are typically associated with obesity, however this has not been made completely clear if diet is a leading cause of obesity, or inadequate heating and exercise. The wild savannah monitor is a specialized insectivore, thus it is recommended to provide a diet largely consisting of various gutloaded invertebrates, such as cockroaches and crickets. The Savannah monitor will occasionally consume lizard eggs in their natural habitat.
Its range extends throughout sub-Saharan Africa from Senegal east to Sudan and south almost to the Congo River and Rift Valley, where they are replaced by V. albigularis.V. exanthematicus is primarily a ground-dwelling species that shelters in burrows, although it is sometimes found in bushes or low trees. In the coastal plain of Ghana, V. exanthematicus juveniles are often associated with the burrows of the giant cricket Brachytrupes.
Varanus exanthematicus is listed as Least Concern by IUCN. The species is hunted for its leather and meat and for the international pet trade. An average of 30,574 live specimens were imported into the US each year between 2000 and 2009; total imports of live specimens into the US between 2000 and 2010 was 325,480 animals. During the same period, 1,037 skins, shoes, and products of the species were imported into the US. Trade in live animals comes mainly from Ghana (235,903 animals exported between 2000 and 2010), Togo (188,110 animals exported between 2000 and 2010), and Benin (72,964 animals exported between 2000 and 2010). During the same period, total worldwide declared exports of skins and products of the species totalled 37,506. However, there is substantial undeclared trade in the species from Sudan, Nigeria and elsewhere