The miniblins from Legend of Zelda: The Wind Waker. They were some of the scariest things in the Zelda series. Don't believe me? Just imagine you can hear this:
didink, didink
Didink, Didink
DIDINK DIDINK DIDINKDIDINKDIDINKDIDINKDIDINKDIDINKDIDINKDIDINKDIDINKDIDINKDIDINK
I apologize for any bad flashbacks.
(For those who didn't play the game: line 1 is soft and you can't see them yet; line 2 is at moderate volume and you are just turning the camera to notice one right behind you; line 3 is loud and you are now surrounded by 15 to 35 of them. This all happens in mere seconds.)