The largest size of this bull ant species is reached by the queen, about 22 to 24 mm (0.87 to 0.94 in) long.
 Males ("drones") grow to 16 mm (0.63 in), and the worker ants average 14 to 18 mm (0.55 to 0.71 in) long.
 Within its genus, M. esuriens is a medium-sized species, as sizes for Myrmecia range from 6 mm (0.24 in) to more than 30 mm (1 in).

The main body of the ant is black with a single segment of the abdomen, the postpetiole, coloured an orange-red.
 The mandibles, antennae, and legs of the ants are also orange-red.
 The hair on the ant is yellow, and is short on the head, thorax, and legs and longer on the gaster.
 No hair is present on the scapes.

The mandibles are long and straight, and of the 11 teeth present, the third, fifth, seventh, and ninth are wider and longer than the other seven.
 The Tasmanian inchman has good eyesight, useful outside of the nest for defence and foraging.

Unusually for ants, the queens are apterous (i.e., wingless), like workers, thus these queens are called ergatoid (i.e., worker-like) to be distinct from alate queens that have wings.
 This corresponds with the consideration of the genus Myrmecia as primitive, with several features, such as the presence of ocelli and a well-defined mesonotum, suggestive of earlier evolutionary development.
The largest size of this bull ant species is reached by the queen, about 22 to 24 mm (0.87 to 0.94 in) long.  Males ("drones") grow to 16 mm (0.63 in), and the worker ants average 14 to 18 mm (0.55 to 0.71 in) long.  Within its genus, M. esuriens is a medium-sized species, as sizes for Myrmecia range from 6 mm (0.24 in) to more than 30 mm (1 in).
The main body of the ant is black with a single segment of the abdomen, the postpetiole, coloured an orange-red.  The mandibles, antennae, and legs of the ants are also orange-red.  The hair on the ant is yellow, and is short on the head, thorax, and legs and longer on the gaster.  No hair is present on the scapes.
The mandibles are long and straight, and of the 11 teeth present, the third, fifth, seventh, and ninth are wider and longer than the other seven.  The Tasmanian inchman has good eyesight, useful outside of the nest for defence and foraging.
Unusually for ants, the queens are apterous (i.e., wingless), like workers, thus these queens are called ergatoid (i.e., worker-like) to be distinct from alate queens that have wings.  This corresponds with the consideration of the genus Myrmecia as primitive, with several features, such as the presence of ocelli and a well-defined mesonotum, suggestive of earlier evolutionary development.
Myrmecia esuriens