With nothing but classic yellow sticky notes and a black pen, artist John Kenn Mortensen (who also goes by Don Kenn) has created countless “doodles” of monsters that can truly terrify. At first glance, many of the monsters appear furry, fluffy, and/or friendly–take a closer look, though, and the drawings become much more menacing. Like true nightmares come to life, here’s a look at some of John’s latest work (thanks, boredpanda.com!). Love what you see? He has a whole book!