the Seeker

From WoWWiki

the Seeker is a title rewarded for having completed the general achievement  3000 Quests Completed.

It is displayed after the player's name, like this:

<name> the Seeker

v • d • e Player Character Titles Arena Vanquisher · Gladiator (Merciless, Vengeful, Brutal, Deadly, Furious) · Duelist · Rival · Challenger · Flawless Victor · Arena Master Battlegrounds Conqueror · Justicar · Battlemaster Exploration the Explorer Feats of Strength PvE Bloodsail Admiral · Scarab Lord · Champion of the Naaru · Hand of A'dal · Conqueror of Naxxramas · Obsidian Slayer · the Magic Seeker · the Celestial Defender · Death's Demise Arena Gladiator (Merciless, Vengeful, Brutal, Deadly, Furious) · Vanquisher Honor System Private · Corporal · Sergeant · Master Sergeant · Sergeant Major · Knight · Knight-Lieutenant · Knight-Captain · Knight-Champion · Lieutenant Commander · Commander · Marshal · Field Marshal · Grand Marshal Honor System Scout · Grunt · Sergeant · Senior Sergeant · First Sergeant · Stone Guard · Blood Guard · Legionnaire · Centurion · Champion · Lieutenant General · General · Warlord · High Warlord Professions Chef  · Salty PvE Jenkins · Champion of the Frozen Wastes · the Undying · of the Nightfall · the Immortal · Twilight Vanquisher · Champion of Ulduar · Conqueror of Ulduar · Starcaller · the Astral Walker PvP of the Alliance · of the Horde Quests the Seeker · Loremaster Reputation the Exalted · Ambassador · Guardian of Cenarius · the Argent Champion · the Diplomat · of the Shattered Sun · the Insane World Events Elder · the Love Fool · the Noble · Matron · Patron · Flame Keeper · Flame Warden · Brewmaster · the Hallowed · the Merrymaker Argent Tournament of Darnassus · of the Exodar · of Gnomeregan · of Ironforge · of Stormwind · of Orgrimmar · of Sen'jin · of Silvermoon · of Thunder Bluff · of the Undercity · Crusader