A Neuron Bomb was a device that Dr. Ivo Robotnik used to short circuit minds of the Walrus Herd in the Frozen North Sea, making them compliant to Robotnik's commands and in a trance like state. When Rotor heard his mother on his old radio, he sets out in his Bathysphere in order to find her. He later discovered that his former herd were under the control of Robotnik by the effects of the device and that Robotnik was planning to use them to freeze the entire planet. (StH: #31)