Named for their round, “bumpy” scales, Knob-scaled Lizards have done well for serious hobbyists, but breeding populations have not been established. Barely 12 cm (5 in) long, they are armed with dagger-like teeth, and savagely defend favored rock crevices. Found from southern Mexico to Guatemala, these tiny terrors are best left to zoos until we learn more about breeding them in captivity.