Doom Patrol in "Black is [theoretically] Black"
Metal Men in "Enter: Douglas!"
*It's a black hole, but it's not a black hole. If you're a Doom Patrol fan, that made perfect sense. And even if not, then you're in for one hell of a ride as the Doom Patrol face off against the most annoying alien this side of G'nort. Who's G'nort? What, do we have to spoon-feed this stuff to you?
Oh, and we send the Metal Men into space. Just because. *Source: dccomics.com