Description

It's showing as available as long as you have the required level. However, the mob you accept it from is hostile unless you are wearing the disguise given as part of https://www.wowhead.com/wotlk/quest=12648/dressing-down OR https://www.wowhead.com/wotlk/quest=12649/suit-up

Accepting (not completing) one of those quests would be a logical pre-requisite. If that's not possible, then completing the pre-requisite quest for either of those quests would be the next best option.

Also: If it doesn't currently, completing the quest https://www.wowhead.com/wotlk/quest=12713/betrayal requires you to hand in the disguise required to talk to the NPC, and would make the quest unobtainable.

Wowhead link

https://www.wowhead.com/wotlk/quest=12652/feedin-da-goolz

Screenshots

Questie & WoW version