Team-ups and partnerships are pretty standard tropes in comics, and they often make perfect sense. Batman teams up with Superman because they're friends and colleagues who share similar goals, personal codes, and motivations. Some of them, however, make a bit less sense, and occasionally they're the end result of the writers just throwing all rationality and convention straight out the window.
Over the past couple of years, DC has really been ramping up the intensity and insanity in their comics with big ridiculous over-the-top stories, and even some bizarre pairings.
The current Justice League series started out last year with stories involving The Flash's Speed Force-powered racecar, Atlantis' towers launching like missiles into space, and the entire Earth becoming a White Lantern, to list a few things - but the weirdest part of the recent comics might actually be the partnerships some characters have forged.
Some of these characters came together to fight an existential threat, and some paired up for more personal reasons. The only things all these partnerships have in common, however, is how utterly absurd they are, and how fun that absurdity is to read.