The first DLC for Bloodborne, "The Old Hunters" is out now on PlayStation 4. It adds new locations, weapons, bosses and armor. There is a small trick by which Bloodborne players can get Simon's BowBlade as their first weapon in "The Old Hunters" DLC. The friendly NPC that is near the very first shortcut back to the first lamp is none other than Simon.
To get Simon's Bow Blade as your first DLC weapon you need to cut his head off immediately, and that's it very minimal effort, it doesn't even requires you to beat a single boss. It is completely up to you to go to him right from the start of the DLC or wait till the very end of the DLC but why wait? Simon is right there waiting for all of you, do what suits best for you.
For those who want to have some clarification on key. You sacrifice the key Simon gives you later if you kill him immediately. This key is an alternative of Chikage which is bloodlettier. So check your options before go ahead.