The avatar of each faction (Eddie, Drowned Ophelia, Doviculus and Lionwhyte) can double team with most or all of their own units to perform a special combo ability. For example, Eddie can gather several Headbangers around him in a mosh pit to bash enemy units out of the way, Drowned Ophelia can dance with her Brides and use their lightning to smite her foes, and Doviculus can leap atop the Slave in a Punishing Party and throw their spears himself. Some units cannot be double-teamed, however, such as the Tick Choppers or Bleeding Death, a demon that is so crazed that it doesn't even listen to Doviculus' orders, much less let him ride it.
In the single player campaign, Eddie can double team with the various animals of the Brütal Land by stunning them with a Shocker attack. Animals summoned through the Call of the Wild solo count as friendly units and can always be double teamed. Eddie can also double team with his Ironheade allies Lars, Lita and Ophelia during some missions.