Tubal Cain
Tubal Cain was a Time Lord who did not like the Doctor's renegade nature.
When an elemental being possessed his TARDIS, the Fifth Doctor sent a distress call to Gallifrey. Shayde was sent to help, and Tubal Cain followed in a massive Battle TARDIS armed with time torpedoes, ready to use them if the situation got completely out of control.
After Shayde was able to get the elemental to leave the TARDIS and enter the Matrix, the TARDIS dematerialised. Panicking, Cain fired at the TARDIS, not realising it was heading to a military base on Gallifrey. The torpedoes exploded before the TARDIS arrived, stopping time for weeks and allowing the Doctor to repair his TARDIS undisturbed. (COMIC: The Stockbridge Horror)
Cain was subsequently demoted for firing time torpedoes over the Capitol. (COMIC: The Final Chapter)
