A sickle is a hand-held agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting succulent forage chiefly for feeding livestock, either freshly cut or dried as hay. The blade's curve is sharp enough that it has been used as an improvised weapon.
Within the Mortal Kombat series, it is first seen used by members of the Brotherhood of Shadow in Shaolin Monks as their sole weapon of choice, snagging and tossing their opponents around with them or tossing them at their opponents.
In Mortal Kombat X and Mortal Kombat 11, Kotal Kahn utilizes sickles as weapons but also uses them to parry attacks. He only uses them as weapons in the Mortal Kombat X Story Mode, and during gameplay he only uses them to parry attacks and projectiles. The sickles are also used in two of his Variations, which are Sun God and Blood God respectively.
Starting in Mortal Kombat 11, however they are now referred to as Hooks. Alongside the Macuahuitl he officially uses them as his weapons regardless of variation. The hooks are used in his Fatal Blow and Fatality called Kat Food. He still uses them to parry attacks in MK11. The hooks are also customizable through the game's gear Kustomization.
In Mortal Kombat 11, Noob Saibot utilizes a sickle that he keeps "sheathed" into his shoulder that goes through his back and protrudes through his chest. He can also summon his Shadow Clone to use it by sending the clone after the opponent. Noob can also duplicate the sickle as seen in his Split Decision Fatality, spawning two for himself and two more for his Shadow Clone. He is also capable of teleporting with the sickle as well. Noob's sickle is also customizable through the game's Kustomization.
Also in Mortal Kombat 11, the character Kollector, a six-armed debt collector, also utilizes a sickle along with a vast array of other weapons during gameplay.