Once you have achieved a level of completed quest, you will be admitted into the champion's guild. Only then it could be unlocked in the guild.
Dragon Slayer is a member's only quest. Unless you are a member, it won't let you do the quest. If you are a member, try doing the other quests to see if you unlock it.
its simple u get a girlfriend and get a life so you dont have to
Non members CAN do the dragon slayer quest. That is how you get rune armor.
From the dragon slayer shop in /join lair
no its a quest
The Dragon Slayer helm was available for purchase with AC coins at one point.
Travel to Dragon Stone and talk to Galanoth. He has a shop that sells dragon slayer armor.
If you look at the Dragon Slayer quest in your quests tab, it should tell you all the recommendations that you will need, if it doesn't or they are lined out - it means that you are ready to start the quest.
Go to below link and go to non-member quest and find dragon slayer quest. It is a good guide with screenshots.
you have to go to dragonstone.
Uh..........Dragon Slayer?
I gave a link for you.