Some principalities of the Archaic Oikumene sponsored hunts for hyperspace worms, ostensibly because they damaged the exotic matter supports of the hyperspace conduits, but also to harvest their neural fluid (a mild intoxicant that enhances spatial awareness). By the end of age, the worms (then known as hyubh) had grown to gigantic size and had become a true hyperspace shipping menace.
They are believed to be extinct, and what is known about the worms only exists in fragmented data from before the collapse.
Recovered data implies that they were probably sophont, and possibly descended from Baseline/Near-Baseline, much like the Runic Dragon.