There are a few quests (one in particular) that gave me trouble for YEARS. Part of it was because the items do not exist until you trigger what you're supposed to do.

For some quests you don't need the exact item (for example if the mob told you it wanted a toy truck, and there were like 10 different toy trucks in the MUD, you could grab any one of them to complete the quest), and for others you need the EXACT item. When a mob needs an exact item they'll usually let you know about the exact item. However, with imm given quests requests, it might be more riddlish in nature.