Bandersnatch was a UNSC emergency code. Used right after combat operations or disasters had taken place, the code represents a radiological- or energy-based disaster.[1]

This code has been used many times, most often when a UEG colony world has been glassed by Covenant forces. The code was also used during the destruction of the Far Isle colony due to massive rebellion,[1] and during the Battle of Earth, after a Covenant Assault Carrier entered Slipspace in Earth's lower orbit and damaged the city of New Mombasa.[citation needed]


  • The word "bandersnatch" comes from the famous poem Jabberwocky by Lewis Carroll in Through the Looking Glass (1871).[2]


  1. 1.0 1.1 Halo: Ghosts of Onyx, page 183: "Bandersnatch" was the code used for radiological- or energy-based disaster. Dr. Halsey had heard this used before from planetary bombardment by Covenant plasma and during the UNSC nuking of the Far Isle Colony to put down the rebellion of 2492.