The Giant Round-Backed Millipede (Pachybolus) is in the Spirobolida Order and Pachybolidae family of round-backed millipedes. It is not an insect, nor an arachnid. It is a diplopod. 

The Giant Round-Backed Millipede has a thick, elongated, cylindrical, segmented body with a hard exo-skeleton. It can be brown-black, red or yellow. Although millipede means a thousand legs, it actually has about 200 legs. It has two pairs of legs per body segment. It has a short head with a number of simple eyes called ocelli – and poor eyesight. It has short antennae.