Cast
From Tardis Wiki, the free Doctor Who reference
A cast was a weapon created by the Great Houses. Insubstantial and mindless, they were hardwired into the Homeworld's noosphere or the operating system of a timeship. When activated, the cast absorbed radiation from the vicinity and changed it into solid baryonic matter or invisible, lower-dimensional strange matter.
The babels were later created as a more advanced version of the casts.
The casts were used in the War in Heaven, but they were effectively useless, especially against the conceptual entities which they somewhat resembled. (PROSE: The Book of the War)