Educative storry, Part 1

A man brought a bird to King Harunur Rashid to sell.
 When he asked the price, he asked for a much higher price than the market price.
 The king wanted to know, why the bird is so expensive? But he does not have a leg!
The man said, forgive yawn!
Although it is common to see, it is actually a special kind of bird.
The peculiarity of this is that when I go hunting, I take this bird with me