The Bottomless Bag was one of the largest containers in World of Warcraft, before the release of Burning Crusade. It is one of two crafted 18-slot bag currently in Kalimdor and the Eastern Kingdoms. See below for the other bags.
This item is crafted by Tailors with a skill level of 300.
The components are:
Patch 1.3.0 (07-Mar-2005): Bottomless Bag requires significantly more mooncloth and two core leather to make now.