"Strontium Dog" is a strip about a mutant bounty hunter, Johnny Alpha, in a post-apocalyptic future where mutants, the result of strontium in nuclear fallout, are a despised minority forced into such dirty work. Johnny works for the Search/Destroy agency, whose initials "SD" are the origin of the bigoted epithet "strontium dog". His mutation involves being able to emit alpha particles from his eyes which let him see through objects and read and influence people's minds. He travels across the galaxy with a sidekick, Wulf Sternhammer, a Viking out of time with a cod German accent, bringing in criminals for money.
The strip first appeared in Starlord in 1978, created by writer John Wagner and artist Carlos Ezquerra. It then appeared in 2000 AD after Starlord merged into it. From 1980 until 1988 Wagner co-wrote with Alan Grant, and after 1988 until 1990 Grant wrote it solo, until "The Final Solution", when Johnny was killed off saving mutants from extermination. Wagner and Ezquerra revived the character in 2000, initially telling stories set before Johnny's death in a revised continuity, then, in 2010, starting a story in which "The Final Solution" is revised in such a way as to bring Johnny back from the dead.