The Battle Bug was a giant beetle-type Invectid machine similar to the more common Battle Beetles commanded by Grasshop. On a mission given to him by Mantid, Grasshop used it to capture an Invectid girl Katydid, but forgot to install the device that would help it determine friend from foe, causing it to attack everything in sight. It is armed with a laser cannon and it gets more powerful the more Katy hates violence and the destruction it causes. Grasshop told Hunter its weakness out of cowardice; slash off both antennae at exactly the same time or they will grow back. Hunter and Aqune managed to defeat it together.