A new Flash rogue is introduced in Flash #117 (Oct 1960): Captain Boomerang. Conceived as a spokesman for the W. W. Wiggins Game Company to publicize boomerangs in the United States, “Digger” Harkness takes up the mantle and is given a costume, which suits him just fine because he was already looking for an opportunity to begin a new phase of his criminal career using a boomerang. That’s not just an “incredible coincidence”, it’s plain ol’ lazy writing!
So yeah, another gimmicky criminal in a silly costume, this time stealing jewelry by having boomerangs scoop up necklaces :-/
Yet even the lazy writing can’t possibly explain how a two-bit criminal who spent years hiding out in the Australian bush is able to create a giant “rocket boomerang” that literally hurtles Flash into outer space.