Doomsday Machine

The Doomsday Machine is a planet-killing machine and a titular major antagonist in the original Star Trek series episode "The Doomsday Machine" - the episode centres around the epic struggle between the crew of the Kirk-era Star Trek franchise and the Doomsday Machine, with the Federation ship doing its best to either destroy or disable the much more powerful super-weapon.

In the MMO game, Star Trek Online about 142 years after Kirk destroyed the first planet killer, a renegade Klingon named B'vat had constructed another planet killer to destroy all who opposed him. But thanks to the actions of a Federation crew and the honorable sacrifice of a Klingon named K'Valk, the second planet killer was destroyed.