A frightened rabbit runs through the forest

A frightened rabbit runs through the forest. The fox sees at him and asks:
- Why are you so frightened? What happened?
- A crazy lion comes to our forest! – the rabbit answered. – He counts tails of animals and if any animal has two tails, this crazy lion cuts off his tail!
- Stupid rabbit – the fox says. – See on your back, you have only one tail.
- I know this – the rabbit says. – But the crazy lion firstly cuts off the tails and only after that counts them!