Lizard tails are often a useful if expendable appendage. Some lizards have tails that they may use to mimic their heads, such as with the sleepy lizard; others may mimic leaves. The tails of many arboreal lizards are prehensile. Iguanas and monitors beat their attackers with their tails.
Many lizards can practice autotomy: lose their tail to break the grasp of a predator. The detached tail continues to wiggle, providing a distracting deception that facilitates escape.
A lizard can regenerate a new tail in ~2 months. The new tail is not a perfect replica. The replacement tail lacks the fine motor control of the original.
Lizard tail loss is not without social consequence, particularly for juveniles of territorial species. High-status juveniles lose face with a lost tail. That lost status may be regained but losing a tail as a juvenile can have a cascading effect on a lizard’s success prospects.
Several invertebrates, including spiders, lobsters, sea stars, crabs, and octopi, are also autotomy artists in being able to regenerate a lost limb.