Zug's capabilities range from the towing of barges to liner docking operations. He and Zip are the Z-Stack equivalents of Ten Cents and Sunshine, in that they are the smaller tugs of the fleet, who work together and are plotting against the other two.

Zip and Zug usually assisted in Zorran’s schemes, such as shoving Big Mac aground onto mudflats so that they weren’t/were not enough Star Tugs to tow in the Duchess and unsuccessfully rescuing their barges from Ten Cents.