In Guardians of the Galaxy, Yondu is seen using a floating arrow as a weapon which he controls by whistling. 

![enter image description here][1]

This arrow is shown to be extremely powerful as it kills a whole squad of soldiers, including their air support, before they can get a shot off.

**What is this weapon and where did he get it?**
 


  [1]: https://i.sstatic.net/1nUcK.jpg