Varanus nebulosus is one of the bigger members of the subgenera Empagusia (MERTENS 1942d). In the past, this was species was ranked as a subspecies of V. bengalensis, but BÖHME & ZIEGLER (1997) raised it into species rank, because both species occur sympatric in northern Thailand and southern Myanmar.
This monitor species also can reach a total length up to 180 cm. The tail is laterally compressed and shows a low double keel on top. It can be 1.3-1.7 times as long as SVL. The animals have a slit like nostril, which is situated closer to the eye than to the tip of the snout. 149-163 scale rows are ordered around mid-body.
The coloration is dark olive-green brown with a yellowish pattern. Small yellow, dark edged spots occasionally replace this drawing. These spots can be ordered in cross-rows. Two dark stripes on both sides of the head, which are more distinctive in young animals, are visible. Youngsters mainly feed on insects (AUFFENBERG & IPE 1983).

The distribution area of V. nebulosus extends from southern Myanmar (Burma), Thailand southern parts of Vietnam, across the Malayan peninsula to Java, Indonesia (MERTENS1942d, AUFFENBERG 1994a).
There V. nebulosus prefers the impenetrable forest along rivers. This species is mainly found on the ground, but can also climb on tress. In young animals this behavior is more strongly distinctive, similar as in V. bengalensis.