Eldratz was a kind of spice. Its effects were so dangerous and even fatal that Hutt criminals refused to deal in it. Eldratz caused those who took it to grow distracted and lethargic, but also pliable and cooperative. Eventually, users experienced a "living death" and entered a coma.
Quarlo I'Shibix operated an eldratz ring on the planet Krann sometime after the Battle of Endor. He made most of his profits from the spice, but he also used it to keep enslaved Kluuzot workers in line as they mined nova crystals for him. After the effects of the spice got to be too incapacitating for a worker, I'Shibix released the Kluuzot. An Ugor on the planet offered the spice for sale, among other wares.