5. The Leprechaun (Four-Leaved Clovers/Wrought Iron/Steal His Gold/A Medalion)
The Leprechaun actually has four glaring weaknesses; two of which are easy to exploit in certain situations, two of which are just easy to exploit in general. He was strong enough to rip a man's heart out and possessed crazy powers such as teleportation and telekinesis and was pretty much unkillable that is until said major weakness came in to play. If you can somehow steal his gold from him, he loses his powers and becomes vulnerable and if you possess a very specific medallion, he can't do anything to you - but those are situational weaknesses. The two weaknesses that make defeating the Leprechaun very easy are his weaknesses to four-leaved clovers and wrought iron. If you can get your hands on either of those things, victory is in the bag.