Jack is a grapple crane, owned by the Municipal Garbage Corporation.
On the day of the Regatta, Warrior had had taken Lord Stinker to the City Dump. When they arrive, Jack tells Warrior that there is not any garbage today, so too does the garbage master. After they convince Warrior about "no garbage", the garbage master explains that they are going to make Lord Stinker, their float for the regatta, look smart using prime colourful garbage.
When the S.S. Vienna came to visit Bigg City Port, Warrior had to find an empty barge as she would have garbage to unload. However, he was having difficulties finding an empty barge and Lord Stinker was full. All the barges which were full could not be emptied because Jack had a cold. A large board was placed next to him reading 'OUT OF ORDER'.
Besides the City Dump, Jack has also worked at the coal yard.
- Jack has no visible mouth. However, it is likely that the inside of his grapple bucket is the mouth.
- Jack is the only non-marine character with a face. All other cranes, business managers, and Puffa spoke through a megaphone.
- Jack's face is located on his garbage grappling bucket.
- A similar grapple crane appeared in the annual story, Loading Grain.
- Jack was renamed to "Scoop" in Salty's Lighthouse.