These enormous mainland geckos are most commonly seen in a melanistic form and often can be ill-tempered. Some of the largest GT's, these Leachies have elongated heads, with a very long tail and a length up to fifteen inches or more. They can max out at 300-400 grams.

Usual colors are deep olive greens with little or no white markings to completely black. Markings can be thin white lines or rows of lighter spots along the sides of the animal, and yellow spotting or markings are not uncommon in mature animals.