Giana - So sorry for not thinking of a dragon fly sooner, so obvious eh, lol.  I remember when I was a kid playing by a pond in the countryside with my younger brother.  A group of three very big green shiny dragonfly's flew over to us and started to buzz about very aggresively.  I swear they were checking us out for a snack, so we ran back to the house and those mean buggers followed us half way at least.  They are cool, thank goodness not as big as they used to be, ever see a fossil of a prehistoric one...  ;)