How can you edit a Kunai to make it like the blade from The Mad Murderer?

How can you make the Kunai into a weapon kind of like the Murder Knife from TMM?

You can, If you change the mesh on the gear, or unless you want to code it entirely from scratch, as far as I know, loleris has not put the knife up for open-source, so you can use the one ROBLOX made.