The Strontium Dogs are more properly referred to as Search/Destroy Agents, mutant bounty hunters operating out of an orbital space station known as The Doghouse in the late 22nd Century. Some of the most notable SD Agents are listed here. They first appeared in the series Strontium Dog, which originated in IPC's Star-Lord comic before becoming a mainstay of 2000AD. When Johnny Alpha, principal hero of the Strontium Dog strip was temporarily killed off, 'Strontium Dogs' was also the name of a short lived replacement strip concerning the adventures of some of his former associates after his death, notably Feral and the Gronk. This series is no longer considered to be in continuity, however.