they are all pretty damn annoying when it comes to those that simply knock you down and kill you. In Metroidvania games it's not as rampant... BUT, Medusa heads,the ones that can turn you to stone will make you suffer. Not only can you be hit at a bad time on a ledge, but you can fall onto a spiked pit, slowly loosing life while in stone... wildst more Medusa heads and other enemy's continue to attack you. Alas poor soul, for Medusa heads are devoid of any purpose in their existence other then ramming their heads into your vulnerable body repeatably.