Tiliqua gigas has an elongated body and very small limbs, which is typical of most skinks of the genus.

Tiliqua gigas evanescens are easily recognized for having slightly more colored speckling on their limbs, a single, centered stripe on the back of their neck, and not always but most often, having very thin body banding.

The Australian northern blue-tongued skink (Tiliqua scincoides intermedia) is recognized as the largest of all the species and subspecies.

What is irrefutable is that T. gigas evanescens is the longest of all the blue tongues, often reaching lengths that exceed 30 inches from snout to tip of tail.

The second subspecies is T. gigas keyensis (Oudemans, 1894), typically called the Kei island blue-tongued skink.