What is the animal that has black rings around its tail?

There are many animals that have black rings around their tails! To narrow it down, I need more information.

Could you tell me:

* What kind of animal are you thinking of? (e.g., mammal, reptile, fish, insect)

* Where does this animal live? (e.g., forest, desert, ocean)

* What is the size of the animal?

* What else do you know about the animal? (e.g., color, markings, behavior)

The more information you give me, the better I can help you identify the animal.