The Avenger of the Airwaves!
Blackrock is a villain who uses television-themed weapons to battle Superman.
Superman first encounters Blackrock after UBC president Samuel Tanner instructs his chief scientist Dr. Peter Silverstone to create a superhero to compete with Superman and the news coverage of Superman that is a mainstay of WGBS. Acting on these instructions, Dr. Silverstone transforms Sam Tanner (without the latter's knowledge) into a masked and costumed hero whom he calls Blackrock. Armed with a TV antenna device that allows him to focus his aggression in the form of radiation, Blackrock engages Superman in a series of battles before the Man of Steel is able to neutralize Blackrock's power and restore Tanner to normal (Act No. 458/1, Apr 1976: "Make Me a Super-Hero!"; Act No. 459/1, May 1976: "Superman's Big Crack-Up!").
In September 1977, Tanner urges Silverstone to bring back Blackrock. Using an obsidian stone, the scientist transforms Tanner's nephew, comedian Les Vegas, into a new Blackrock. Able to transform his body into black particles and ride "waves of broadcasting signals in the atmosphere," the new Blackrock attempts to take credit for the deeds of Superman and in the course of a battle with Superman, the two exchange identities, so that Blackrock thinks he is Clark Kent and Clark Kent thinks he is Blackrock. After young Jonathan Ross manages to convince Clark that he is really Superman, Blackrock is quickly defeated and Les Vegas is restored to normal, with no memory of his career as Blackrock or the secret identity of Superman (S No. 315, Sep 1977: "Good Evening Superman--I'm Clark Kent...and You're Not!").