The Crysknife is a powerful melee weapon that kills any monster in a single hit. The Crysknife permanently replaces the whip when it is found, and is the only weapon upgrade that does not need to be carried in the hands. Despite its incredible offensive power, it may still be safer to attack enemies with ranged attacks to avoid getting too close to dangerous monsters. The knife has no effect on Olmec, the Ghost, or Magma Men. Croc Men will avoid damage by teleporting away before you hit them.