The Zigg'raugglurr is a mysterious fourth-dimensional alien being dwelling beyond the Horizon.
According to the Oracles, the Zigg'raugglurr exists fourth-dimensionally, and dwells beyond the Horizon, which is the only thing preventing it from regular contact with the Earth. It has a vast understanding of time and space, and perceives time in an almost Euclidean geometry as humans and mages perceive space. Since the creature does not exist in a three-dimensional reality only portions of it may be perceived, giving it the appearance of segmentation. To perceive it in full, Correspondence and Time effects are presumably required.
The Zigg'raugglurr hunts and feeds on Quintessence throughout Earth's space-time continuum, stealing the Quintessence from times in the past before the Gauntlet and the Horizon blocked its access. It gathers what Quintessence it can before it is chased away by Paradox spirits. These powerful Paradox spirits hunt for past anomalies to the present in order to prevent the Zigg'raugglurr from wreaking havoc in Earth's past.
The Zigg'raugglurr have worked with the Nephandi in some manner, possibly in a bargain to allow the Zigg'raugglurr to pass through the Horizon, but the details of this cooperation are unclear.
Besides knowledge of and the ability to perceive and move through time and space, the Zigg'raugglurr is also able to harvest Quintessence. What other abilities they may have is unknown.