Frequency Zero was a frequency that was audible to the purrgil, space-faring creatures capable of hyperspace travel. By 1 BBY, the frequency was no longer in use. During the liberation of Lothal, Ezra Bridger tasked Mart Mattin, Wolffe, and Cikatro Vizago with transmitting a signal on Frequency Zero. This drew a large pod of purrgil which wiped out the blockade by Grand Admiral Thrawn's Seventh Fleet over Lothal and carried Bridger, Thrawn, and the Imperial Star Destroyer Chimaera into the depths of space.
- Star Wars: Battles that Changed the Galaxy