Hello This Is OgreKiller7 and today ill show you how to make a graplling hook your need 1.7.8 and up
first what you do is get a command block (do /give (name) Minecraft:command_block place it down right click And Type /setblock ~ ~1 ~ air click done place another command block a space up right click and type /setblock ~ ~-1 ~ redstone_block
place a redstone block in the space bewteen the command blocks and thats already halfway done! then place a command
block on the side of the redstone block and type //tp @p @e[name=unknown] and take out a fishing rod
 throgh it and there you go!!!!