The big blue meanie, otherwise known as Yondu, is one of Guardians of the Galaxy’s most endearing characters. It’s not because of his weird sense of humour or striking skin tone, but because he can whistle and make people die. That’s pretty damn cool.

But how does it work? Director James Gunn took to Twitter to answer the questions about the yaka arrow:

Scientific breakdown of Yondu’s yaka arrow by @Sci_Phile https://t.co/YLjz3aCzx5 — James Gunn (@JamesGunn) June 8, 2017

Side note on the yaka arrow: the whistle sound is picked up by the headpiece and is transmitted wirelessly to the arrow. — James Gunn (@JamesGunn) June 8, 2017

2nd side note on the yaka arrow in explanation of an unnamed spoiler: the headpieces are fairly common/simple; the arrow is incredibly rare. — James Gunn (@JamesGunn) June 8, 2017

Mary Poppins is smarter than he looks.

Guardians of the Galaxy Vol. 2 is currently still in theaters, though you may have to be quick if you want to catch it before home release. Our own Kieran had plenty of good things to say about it in his review:

“With Guardians of the Galaxy Vol. 2, James Gunn takes everything that made the first film such a hit and capitalises on doing it again. It might not move things along in the MCU as much as people had hoped, but it’s an absolute blast from start to finish – a blast lined with great tracks which people will be singing all Summer.”