Mutant Lizards are made up of one piece and are made of a flexible rubber-like material. They have no real joints that allow for posing of limbs and other such parts. Each foot has a hole on the underside large enough to fit onto a LEGO stud, but they cannot be securely connected.
Physically, Mutant Lizards are slightly taller than standard minifigures but are much longer than minifigures (mainly due to their tail). They appear in three colours: black, dark orange, and purple. They also have differently-coloured spots along their backs: black lizards have blue (in 7473/7294) or lime green (in 7475/7296) spots; orange lizards have yellow spots; and purple lizards have blue spots. Each Mutant Lizard has white eyes and teeth.
In the Dino Attack plot, Mutant Lizards had different powers, depending on the breed. These included acid-spitting, darkness, stealth, fire-breathing, and colour-changing. Crossbreeds usually resulted in the offspring having both powers of its parents.[source?] They were highly adaptable and skilled at infiltration.
Finding their strength in numbers, Mutant Lizards make up the bulk of the dinosaur population in the Dino Attack theme.
- The Mutant Lizard's brick is internally named "54125 Compy", implying that it was based on the dinosaur Compsognathus.
- Green, yellow, and red Mutant Lizards appear in the online Dino Attack game, even though they do not appear in these colorus in sets.
- 7473 Street Sprinter vs. Mutant Lizard (1)
- 7294 Dino Quad (1)
- 7475 Fire Hammer vs. Mutant Lizards (3)
- 7296 Dino 4WD Trapper (3)