Also called the spiny-tailed monitor or ridge-tailed monitor, Ackies dwarf monitor (Varanus acanthurus) has a long tail that is ringed with spines or ridges. Wedging its tail into a rock crevice, the spines help to hold the monitor in place and make it difficult for a predator to pull the lizard out.
- Where to see them: Northern Australia
- Length: Up to 2 ft
- Weight: Up to 12 oz
- Lifespan: More than 10 yrs
- Habitat: Rocky outcrops
- Diet: Insects and small reptiles