How do you get abyssal whip on runescape

There is a total of 3 ways you can get a whip:

1. Killing Abyssal Demons and getting one as a Rare Drop ( Level 85 Slayer needed. )
2. Buying one at the Grand Exchange / off another player.
3. Killing a player either on a Bounty Hunter World or a normal pvp world.
   

(To obtain an abyssal whip, you must also have membership.)