[citation needed] C. gerrardii is a relatively large lizard of up to 45 cm (18 in) total length (including tail).

C. gerrardii has a slate-grey to fawn dorsal ground colour with dark grey to brown or black cross bands.

Its main diet consists of snails and slugs, for which it forages during twilight hours and at night in summer, and also during the day in cooler months.

C. gerrardii is a good climber, using its semi-prehensile tail as a supporting aid and, although only partially arboreal, climbing trees to feed when necessary.

When threatened, C. gerrardii raises its body off the ground to appear larger, and flickers or vibrates its tongue rapidly similar to snakes.

[citation needed] In C. gerrardii courtship occurs in early spring for a period of six weeks, during which time males have been observed to fight.

After an estimated gestation period of 101 to 110 days, females produce large litters of 20 to 30 (largest recorded: 67) live-young in early summer.

The tongue and mouth are dark blue and the ventral surface is black in juveniles, changing to pink and mauve respectively after about three months.