Tiger snake of distinct populations, which may be isolated or overlapping, with extreme variance in size and colour. Individuals also show seasonal variation in colour. The total length is typically about 1.2 metres The patterning is darker bands, strongly contrasting or indistinct, which are pale to very dark in colour. Colouration is composed of olive, yellow, orange-brown, or jet-black, and the underside of the snake is light yellow or orange. The tiger snake uses venom to dispatch its prey, and may bite an aggressor; they are potentially fatal to humans. Tolerant of low temperatures, the snake may be active on warmer nights.
Tiger snake systematics previously applied, but most agree a revision of the genus is needed. Names for these subdivisions include the western types, appended to both species names as "occidentalis" (Glauert 1948) The island groups have also been described as subspecies: Chappell Island tiger snake as "N. ater serventyi" (Warrell, 1963), King Island and Tasmanian tiger snakes subspecies as "N. ater humphreysi", (Warrell, 1963) and the Peninsula tiger snake as "N. ater niger" (Kinghorn 1921). Island populations of "N. scutatus" have evolved larger heads to cope with large prey animals. Young populations have larger heads by phenotypic plasticity, whereas large heads have