The following contains spoilers for Avengers #55, now on sale from Marvel Comics
In Avengers #55 (by Jason Aaron, Javier Garron, David Curiel, and VC's Cory Petit), the Serpent Society returned in full force with a more nefarious mission statement than ever before. Now under the influence of Mephisto, the team that had seemingly gone straight were now cold-blooded killers making sacrifices for the demon. But before they resorted to such violent ends, the Serpent Society once represented a collection of villains that had successfully shown how a group of villainous characters could work together constructively.
In Captain America #310 by Mike Gruenwald and Paul Neary, Captain America came face to face with one member of the Serpent Society, Anaconda. At the time, he was unaware of the larger cabal that had been built, even though he was prepared to defeat this single adversary. However, the Serpent Society as a single entity represented a major threat and had the potential to reformat all of the villains of the Marvel Universe.
Before Cap faced off against Anaconda, it's revealed that Sidewinder had sent out invitations for all of the snake-themed villains of Marvel to meet for a business opportunity. Although Constrictor quickly stormed out, those that stayed were treated to the deal of a lifetime. All they had to do was work for Sidewinder, and they were guaranteed everything from paychecks, insurance, pension plans and most importantly, the promise of never being caught. Since then, no other villain team has unionized to this degree, and it begs the question of why not?
It has long been considered that bickering and selfishness would mean the downfall of any villainous pairings in the Marvel Universe going all the way back to the Masters of Evil. However, the Serpent Society lasted for quite some time, albeit with changes to the roster from time to time. No matter the defeats, the benefits they had obtained while on the team proved that it was well worth the potential risk of fighting heroes. There's also the lasting benefit for their reputation and the supervillain community as well.
Since these villains fight as a union, they have proven that goals can be achieved if there's a constructive way to work together. While none of the other enemies in the Marvel Universe listened, the Society proved to be one of the most enduring teams to face off against the heroes. It also showed the level of camaraderie between them as none of their teammates ever acted selfishly and even went straight as a team when the time came. As their recent murderous tendencies has shown, there is also the fact that if they were ever to break bad to the point of murder, their organization would make them one of the deadliest forces imaginable. But since they typically focused on small-time scores (when a demon doesn't influence them) and a comfortable living, it actually benefitted the planet.
They may not be the most recognized villains in Marvel Comics, but the Serpent Society endured because they knew how to work as a business, union, and a field team. There were no moments where one member was better than the other, and they showed that fulfilling promises could lead to an unbreakable bond of trust. While they're still bad guys through and through, they should have been used as a template for other enemies to follow rather than shunned for daring to do something different. However, not all enemies in the Marvel Universe are team players when they could take all the rewards for themselves -- even though that always ends in inevitable defeat.