The Pack is a group of E.V.O.s working under the command of Van Kleiss.
In Ben 10 Comics
They appear on the Action Pack 65, where they enter into a space-time portal and arrive in the reality of Ben in search of something or to escape the Rex team, are eventually followed by the team of Rex (Rex, Six and Bobo). To stop them. Ben, Gwen and Kevin are joined by Rex, Six and Bobo.