Gangs are a group of characters that an MBer has on their account. They are often added for fun and to make stories and skits about. An MBer's gang members can be your OCs or your favorite characters from your fandoms. They always post in colors that differ from the MBer's normal posting color, and their names/initials are usually listed in the MBer's signature, each typed in the gang member's unique color/font. MBers often ship their gang members together, and many ship themselves with a gang member.
Verity was the first person with the idea for gangs on the SAMB, when she brought a few of her favourite characters onto her account during the summer of 2014. Gangs became more popular in about October or November of that same year.
The majority of SAMBers have gangs, although not all do.