About Varanus rudicollis (Gray, 1845)
Varanus rudicollis, commonly known as the black roughneck monitor, is a medium to large species of monitor lizard. Average adult individuals reach 3–4 feet (90–120 cm) in total length, and a maximum reported length for the species is 5 feet (150 cm). Adult black roughneck monitors are easily identifiable by the large pointed scales that cover their necks. They have a slender, long-bodied build and a distinctly pointed snout. This species is known for having a very calm temperament; in captivity, it rarely bites or uses tail whipping as a defensive behavior. When threatened, black roughneck monitors prefer to flee, and may also urinate, defecate, puff up their throats, or enter a tonic immobility response (often called "going necrotic") by closing their eyes to appear dead.