There is one known maker of mechanical squids, Captain "Quailfurn's" or "Quail Furn's" Mechanical Squid Works. An example of this firm's products ✣ can be found in the cistern of Castle Heterodyne. Fräulein Snaug describes these mechanical squids as being "impertinent" ✣ after returning from a search of the cistern for parts. Agatha later learns, much to her delight, that Snaug's description of the squids is fairly accurate ✣ . It would seem that Klaus Wulfenbach is not the only spark capable of picking the right monster for the right job.
Later. it is demonstrated that the Squid Clanks also possess an internal control cockpit that permits a human operator to use it as a vehicle & load-lifter. It has not as yet been shown to be usable as a submarine, although this seems probable.
It also has a fuel cap on the back marked "Unleaded".