I'm not going to give you the Blue Oyster quest until you complete my other quests! You may still have a few stray cats left to discover in Marleybone.
If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.
For Zeke to give you another "Find" quest, you have to do all of the ones in earlier worlds (except Grizzleheim). As said, you have to round up the rest of the stray cats in Krokotopia first.
If you're having trouble finding them, Wizard101 Central (an approved fansite) has several guides available. Here's a simpler one: