The Nort Ship Z is a secret ship from Tyrian. It is the strongest ship in the game, and can only be obtained after beating the game in the hardest difficulty. It can also be used on the Super Arcade Mode by typing NORTSHIPZ on the title screen.
TOP SECRET: This ship is on loan from Nortaneous' personal hanger. The rent on this ship is very high, but it's incredibly powerful.
The only way to describe what this ship does is to fly it and see for yourself. Nothing on the screen is safe with its special weapon active.