Zug is an ambitious, young tug who is Captain Zero's fourth tug, and one of the Z-Stack switchers. He is usually seen working with Zip. He is used for a wide variety of tasks around Bigg City Port. He speaks with an Estonian accent.
Zug mainly works with Zip, and likes to think of himself as the intelligent one. Compared to Zip, he certainly is intelligent and practical, but he is not as smart as the other tugs. He comes up with devious plans for him and Zip to use. He is a scheming sort of tug, though his plans rarely if ever work as planned. Despite being best friends with Zip, Zug basically commands him, who's too frightened to make any good suggestions.
Zug is often left out of plans and sent to do a completely different job compared to the others regardless if he may be capable of managing by himself or not.
Zug's capabilities range from the towing of barges to liner docking operations. Like the rest of the Zero Marine, he is based on the Moran Fleet tugs of the 1920s.
Zug is sneaky, cowardly and he needs the other Z-Stacks around for courage. He is intimidated by the main Z-Stack Zorran and has a tendency to be somewhat nervous and jittery around him. However, as seen in Trapped, he did initially keep his cool while around Zorran, only to panic when Zorran's impatience landed the smaller tug in trouble.
At one point, Zorran callously abandoned him trapped Up River (with seemingly all the Star Tugs, but it turned out only most of them were trapped) when they accidently crashed an old tramper across the river. Zug worked with the Star Fleet to get it out of the way since he was stuck on the other side, but he never complained. He was also shown to be very supportive towards O.J.'s plan to ram it with a line of barges, despite it not working as expected; he even helped out in the attempt. They were all freed when Billy Shoepack effortlessly helped by blowing up the tramper with dynamite.
Zug 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. Zug has major roles in most episodes, and a majority of stories focus on him as a major character in some way.Zug's whistle has a hooting quality that sounds very much like a squeeze horn, but deeper.
Top Speed- 20-25 knots
- After Tugs' production ended, Zug's model was purchased by the Star Tugs Company, an organisation which aimed to restore and preserve the models.
- It is currently unknown if Zug's other face masks still remain in existence.
- In a few episodes of the Finnish version, Zug is called Suppala; sometimes he is just called Sisu.
- Zug's voice and face is based on Hungarian-born American character actor, Peter Lorre.