It is unknown if they are involved in other "criminal" activities, but the chances are there. They seem to be a ruthless group that cares nothing for the well-being of others. They can be generally heard speaking Spanish to one another.
Their outfits are designed with skeleton bones, such as spines and ribs on their jackets along with bandannas and other headgear blocking their faces. These masks have skulls on them, complete with teeth and eye sockets so they can see. It is unknown if their skeleton motif was used prior to the outbreak.
They are usually heavily armed.
Post Apocalypse Edit
After the outbreak, (add details).
Escorpion has what seems to be an AT4 that he uses to shoot at 10K, temporarily deafening him. Interestingly an AT4 can only be fired a single time before it is discarded as it can not be reloaded but it is seen being fired several times in the show; a possible goof. The Zeros have lengthy resources, however, so it is possible that he simply had multiple weapons.
Zeros had audio only appear in this episode.