The X345 Super Weapon is a huge plasma gun capable of destroying a planet. In fact, it did just that with Planet X. The X345 has the power of ten thousand kilograms worth of Acid Fire. It was wielded by Wee Bee Gee Jee in an attempt to become all-powerful by taking Planet X's core energy. It is currently being stored on Asteroid X345.
The weapon was named X345 because it was supposed to turn Planet X into 345 asteroids, but it actually turned it into 2397 asteroids.