some types, it is used as defense or protection
Tadpole's tails do not fall off by themselves, but they can be bitten off. I do not know if their tails grow back. I am trying to figure that out right now because 4 of my tadpole's tails got bitten off.
Yes, leopard geckos' tails can fall off easily as a defense mechanism called autotomy.
NO NO NO NO NO NO IT NEVER CAN AND NEVER WILL
No
Some salamanders can detach their tails when attacked and later regrow them.
No, a donkey's tail does not fall off. This is in reference to the animal. However, donkey tail plants do tend to fall off.
Yes.
No they can not, but that's a good question.
Yes, they have a similar body shape to that of a newt or lizard.
Most are small, and can hide in logs or under rocks. Some have bright colors to show that they are poisonous, and their tails can come off and regrow. The tails still move, so the predators think that they still have the salamander/newt.
No, they can be pulled of but the squirrel will probably bite you before then, or the tail can be cut off which I highly recommend not doing.
Yes, salamanders can regenerate their tails and legs. See related link