Warning: the following contains SPOILERS for Peacemaker.
Peacemaker's various DC easter eggs, neither the Butterflies nor the Cow are directly based on anything from DC Comics or the DCEU.
The massive Cow, which made its first appearance in Peacemaker season 1, episode 7 "Stop Dragon My Heart Around," is what supplies the Butterflies with the amber honey-like liquid that sustains them. This is the only type of food that the Butterflies can eat, which means that the cow is crucial not just to their survival, but also their plans of world domination. As Peacemaker (John Cena) and the rest of the 11th Street Kids make their way to the barn where the Cow is being kept, audiences get a full view of the large alien creature.
Peacemaker's Cow or the Butterflies may not be based on anything from the comics or the DCEU, but they do echo elements from James Gunn's horror movie roots. In fact, the way Butterflies attack and take over the minds of humans is very similar to how the leeches attack in 2006's Slither. Moreover, in Slither, one infected character eats enough food to balloon to a size and shape that's similar to the Cow. Another clue about the Cow's true origins is how it has the body and limbs of a caterpillar, while its eyes are closer to that of a spider, suggesting that it's an entirely different species. While it's unclear whether the Cow is a slave or willingly giving up its nutritious amber secretions, the way the Butterflies operate suggest that it's the former. Depending on how the 11th Street Kids play their cards, they might be able to use this to their advantage in the fight with the Butterflies.
Curiously, there's a chance that the Cow could've been inspired by a character from DC's Swamp Thing. In Saga of the Swamp Thing, there is a morbidly obese vampire queen that's bloated from carrying countless vampire eggs, cared for by her vampire underlings – similar to how the Butterflies take care of the Cow. Another potential source of inspiration for the Cow is DC's The Omega Men series from the late '70s and mid-'80s, which was filled with all sorts of alien species – although none directly resemble the Cow in Peacemaker.
Peacemaker is the perfect place to introduce new and original creatures to the DC franchise, and James Gunn certainly takes advantage of this opportunity every chance he gets. While fans can now stop speculating about what the Cow looks like, new theories abound regarding the Cow's true origins and whether or not it'll have a larger role down the line. Considering how many were disappointed with the White Dragon as a villain, either the Butterflies or the Cow itself need to step up their game.
Peacemaker releases new episodes on Thursdays on HBO Max.